If you have been searching for baked spaghetti with Alfredo sauce that actually tastes like something you built rather than something you assembled from jars, this is the recipe. Most versions of this dish — including the ones that went viral on TikTok — rely on store-bought Alfredo that separates in the oven and a meat sauce that never gets past the flavor of jarred marinara. This version fixes both of those problems with techniques that add minutes, not hours: a roux-stabilized homemade Alfredo that clings to every strand of pasta through the full bake, and a meat sauce that gets a tomato paste deglaze step most recipes skip entirely. The result is a baked spaghetti casserole with Alfredo sauce and meat sauce that has real depth, real creaminess, and the kind of layered contrast that makes people scrape the pan.
What Is Baked Spaghetti with Alfredo Sauce?
Baked spaghetti with Alfredo sauce is a layered pasta casserole made by tossing cooked spaghetti in a creamy homemade Alfredo sauce, spreading it into a baking dish, topping it with a savory meat sauce, covering everything in shredded mozzarella, and baking it until bubbly and golden. It became one of the most searched baked pasta recipes on the internet after spreading widely on TikTok, where home cooks filmed the dish going into the oven and coming out in gooey, pull-apart layers that earned hundreds of millions of views. The dish works because of contrast: a silky white cream sauce coats the pasta underneath while a bold tomato-forward meat sauce sits on top, and the mozzarella melts between the two layers to bind everything into a cohesive, scoopable casserole. This version uses a roux-based Alfredo rather than jarred sauce, which keeps the cream layer stable and clinging through the entire bake instead of pooling and separating at the bottom of the dish.
Why This Baked Spaghetti with Alfredo Sauce Works Better Than Most Recipes?
The overwhelming majority of recipes for this dish, including many popular ones, use jarred Alfredo sauce. Jarred Alfredo works in a pinch, but it has one serious structural problem in a baked casserole: it separates. The fat and liquid in jarred Alfredo are held together by stabilizers that are formulated for room-temperature shelf storage, not for 30 minutes in a 350-degree oven. When you bake it, those stabilizers break down and you end up with a greasy pool of cream at the bottom of the dish with the pasta sitting in it rather than coated by it.
The fix is a roux. When you cook a tablespoon of flour into the butter before adding the cream, you create a starch-stabilized emulsion that holds together under oven heat. The sauce stays thick, stays clinging, and stays silky through the entire bake time. This is not a complicated technique but the result is completely different from what jarred Alfredo produces in the oven. An optional ounce of cream cheese stirred in at the end of the Alfredo adds a second layer of stability and a gentle tang that rounds out the richness.
The meat sauce problem is different. Most recipes brown the beef, add the jarred marinara, and simmer for five minutes. The flavor that it produces is fine but flat. The deglaze step changes everything. After the beef is browned, you stir in tomato paste and cook it directly in the rendered fat for two to three minutes until it darkens from bright red to a deep brick color. You are caramelizing the concentrated sugars in the paste through a process food scientists call the Maillard reaction — the same chemical process that browns a steak or darkens bread crust — building flavor compounds that no amount of simmering jarred sauce can replicate.
Then you deglaze with a splash of red wine or beef broth, which lifts all the browned bits from the bottom of the pan — that fond is concentrated flavor that would otherwise get left behind. The balsamic vinegar finish at the end is the last piece. Half a teaspoon stirred in right before the sauce goes over the pasta does not make the sauce taste like balsamic. It provides just enough acidity to lift every other flavor in the dish and prevent the whole casserole from landing as one heavy, uniform note.
The Secret Is in How You Prep the Pasta
And then there is the pasta itself. Coating the drained spaghetti in butter and a splash of starchy pasta water before tossing it with the Alfredo is the kind of step that sounds optional until you understand what it does. The starch in the pasta water helps the Alfredo cling to every strand rather than sliding off. The butter creates a fat barrier that slows how much moisture the pasta absorbs from the tomato sauce during baking. The result is noodles that stay silky and cohesive instead of bloated or gummy.
Ingredients for Baked Spaghetti with Alfredo Sauce
Red Sauce Ingredients
2 tablespoons olive oil | 1 cup onion, chopped | 1/2 cup green bell pepper, chopped | 1 tablespoon garlic, minced | 1 pound ground beef (80/20) | 2 tablespoons tomato paste | 1/4 cup red wine or beef broth | 1 1/2 teaspoons salt | 3/4 teaspoon black pepper | 1 tablespoon Italian seasoning | 1/2 teaspoon red pepper flakes, optional | 1 1/2 (24-ounce) jars spaghetti sauce | 1/2 teaspoon sugar or 2 tablespoons finely grated carrot | 1/2 teaspoon balsamic vinegar
Pasta
1 pound spaghetti | 1 tablespoon salt for the pasta water | 1 tablespoon butter | 1/4 cup reserved pasta water
Alfredo Layer
1/2 cup butter | 4 cloves garlic, minced | 1 tablespoon flour | 1 1/2 cups heavy cream | 1/2 cup whole milk | 1 1/2 cups Parmesan, freshly grated from a block | 1 ounce cream cheese, optional but recommended | Pinch of freshly grated nutmeg
Cheese Layer
2 cups mozzarella, shredded from a block and divided | 1/2 cup provolone or fontina, optional for better melt and a deeper flavor
How to Make Baked Spaghetti with Alfredo Sauce Step by Step
Time needed: 1 hour
- Build the Meat Sauce
Heat the olive oil in a large skillet over medium heat. Add the chopped onion and bell pepper and cook until softened, about five minutes. You want them translucent and a little sweet, not caramelized — keep the heat at medium and give them room in the pan. Stir in the garlic and cook for another 30 seconds until fragrant. Add the ground beef, breaking it up with a wooden spoon, and cook until no pink remains and the beef reaches the USDA safe internal temperature of 160°F for ground beef. Tilt the pan and spoon off most of the rendered fat. Leave just enough to cook the tomato paste in — about a tablespoon’s worth.
Now the step that changes everything: stir in the tomato paste and press it into the meat and the fat left in the pan. Let it cook there for a moment without stirring, then fold and stir, then let it sit again. Do this for two to three full minutes. You are looking for the paste to shift from a bright, vivid red to a darker, more muted brick color. When you see that color change, the sugars in the paste have caramelized and you have built the deep, roasted backbone that makes this sauce taste like it cooked all afternoon. Pour in the red wine or beef broth and scrape the entire bottom of the pan clean — every bit of that browned residue goes back into the sauce as flavor.
Add the salt, pepper, Italian seasoning, red pepper flakes if you are using them, and all the jarred spaghetti sauce. Stir well, reduce the heat to medium-low, and let the sauce simmer uncovered for 10 to 15 minutes until it thickens noticeably. You want it to look like it holds its shape when you drag a spoon through it, not like a pourable liquid. A watery meat sauce is the most common reason baked spaghetti casseroles come out soggy at the bottom, so do not rush this step. Finish with the sugar or grated carrot — both smooth out the acidity in the jarred sauce — and then stir in the balsamic vinegar. Taste and adjust salt. Set aside.
- Cook and Prep the Pasta
Bring a large pot of water to a boil and add a full tablespoon of salt. The water should taste lightly briny — this is the only opportunity you have to season the pasta itself, and under-seasoned pasta will make the finished casserole taste flat, no matter how good your sauces are. Add the spaghetti and cook for about two minutes less than the package directions indicate for fully cooked pasta. The noodles should have a definite bite and some resistance in the center — they are going to cook further in the oven, and what feels underdone right now will be perfect after baking.
Before you drain, scoop out at least 1/4 cup of the starchy pasta water and set it in a small bowl. Drain the spaghetti thoroughly, then return it to the pot with the heat off. Add the tablespoon of butter and the reserved pasta water and toss until the butter melts completely and every strand is coated. This combination of fat from the butter and starch from the pasta water creates a coating that accomplishes two things: it helps the Alfredo adhere to the noodles evenly, and it slows down how quickly the pasta absorbs moisture from the tomato sauce during baking. These are not small differences in a casserole that spends 30 minutes in a hot oven. - Make the Alfredo Sauce
In a medium saucepan over medium heat, melt the butter completely. Add the minced garlic and cook for about 60 seconds, stirring, until fragrant but not at all browned — browned garlic will make the Alfredo taste bitter. Add the flour and whisk it into the butter immediately, cooking and stirring for a full minute. This is your roux, and it needs that full minute to cook out the raw flour taste. If you can smell something faintly nutty and toasty, you have done it right.
Slowly pour in the heavy cream in a thin, steady stream while whisking constantly. If you pour too fast, the roux cannot incorporate it evenly, and you will get lumps. Add the milk the same way. Once all the liquid is in, let the sauce come to a gentle simmer and cook, whisking occasionally, for three to four minutes until it thickens enough to coat the back of a spoon. Reduce the heat to low. Add the Parmesan in three or four additions, waiting for each addition to fully melt before adding the next. Add the cream cheese if using and stir until it disappears into the sauce. Finish with the pinch of nutmeg and taste for salt.
Do not let this sauce boil after the cheese goes in. Parmesan is a hard, aged cheese with a low moisture content, and it behaves very differently from softer cheeses under heat. At a gentle simmer, it melts beautifully and smoothly. At a rolling boil the proteins seize and the fat breaks out. No amount of whisking will fix a broken Alfredo once that happens. Keep the heat low, stay patient, and pull the pot off the heat the moment the sauce looks silky and coats the spoon cleanly. - Combine the Pasta and Alfredo
Pour the Alfredo sauce over the buttered spaghetti and toss with tongs until every strand is evenly coated. Take your time here — you want the sauce distributed all the way through the pasta, not just on the outside of the bundle. Add one cup of the shredded mozzarella to the pasta and fold it in. This step binds the pasta layer into a cohesive base. The mozzarella melts into the Alfredo and gives the bottom layer a slightly custardy, stretchy texture that holds together when you scoop it instead of collapsing into a pile of loose noodles.
- Assemble the Casserole
Preheat your oven to 350 degrees Fahrenheit. Grease a 9×13-inch baking dish thoroughly with butter or cooking spray. Add the Alfredo spaghetti to the dish and spread it into an even layer, pressing it lightly into the corners.
Spoon the meat sauce evenly over the top, making sure it reaches all the way to the edges so every serving gets both layers. Scatter the remaining mozzarella and the provolone or fontina over everything.
If you are using a mix of provolone or fontina with the mozzarella, toss them together before you scatter them — the provolone and fontina melt at a slightly lower temperature and mixing them ensures you get that blend of flavors in every bite of the cheese topping. - Bake, Rest, and Serve
Cover the baking dish tightly with aluminum foil and bake at 350 degrees for 20 minutes. This covered period traps steam and heats the casserole through without over-browning the cheese before the center is hot. Remove the foil and bake for another 10 minutes until the cheese on top is bubbly, melted, and lightly golden in spots. If you want more color on the cheese, turn on the broiler for the last two to three minutes and watch it closely — it goes from golden to burnt quickly under the broiler.
Pull the casserole out of the oven and let it rest uncovered for at least five to ten minutes before serving. This resting period is not optional if you want clean, distinct slices or scoops. Right out of the oven, the filling is loose and molten and will run when you cut into it. After five to ten minutes, it sets just enough to hold its shape, and the layers stay visible in each portion. Serve with tongs or a large spoon, going all the way down through both layers so every plate gets the full experience.
Tips for the Best Baked Spaghetti with Alfredo Sauce Every Time
Grate Your Own Cheese for the Creamiest Alfredo Spaghetti Bake
Freshly grated cheese makes a noticeable difference in this casserole. Pre-shredded mozzarella and packaged Parmesan are coated with anti-caking ingredients — usually cellulose or potato starch — that prevent the cheese from melting smoothly, and the difference in the finished sauce is noticeable. Grating a block of low-moisture mozzarella and a wedge of Parmigiano-Reggiano right before using them creates a creamier Alfredo sauce and a perfectly melted cheesy topping. It only takes a few extra minutes and is absolutely worth it.
Choose 80/20 Ground Beef for a Richer Spaghetti Casserole
Using 80/20 ground beef gives the sauce a richer flavor and better texture. The extra fat helps the tomato paste caramelize properly while carrying the flavors of the garlic and Italian seasoning throughout the sauce. After browning the beef, remove most of the excess grease but leave a little behind so the tomato paste can cook properly. The sauce simmers long enough that the finished casserole will still taste balanced and hearty, not greasy.
Take Your Time Building the Homemade Alfredo Sauce
A smooth Alfredo sauce comes from slowing down and letting each step work properly. Give the roux a full minute to cook, slowly pour in the cream, and add the Parmesan gradually over low heat. Rushing the process can cause the sauce to separate or become thick and stringy. If the sauce starts looking too thick while cooking, whisk in a spoonful of pasta water off the heat to help bring it back to a silky texture.
Always Rest Your Baked Spaghetti Casserole Before Serving
Allowing the casserole to rest for about 10 minutes after baking makes a surprisingly big difference. Resting gives the layers time to settle so the casserole slices cleanly and holds its shape. Serving it right away will still taste delicious, but waiting a few minutes creates a more structured and creamy final dish.
Common Mistakes to Avoid With This Baked Spaghetti Casserole
- Cooking the spaghetti just to al dente makes a huge difference. The pasta will continue cooking in the oven, so leaving a little bite in the center keeps the casserole from turning soft and mushy.
- Taking an extra 2 minutes to cook the tomato paste in the pan gives the sauce a deeper, richer flavor that tastes much more homemade.
- A thick meat sauce works best for this casserole. If the sauce looks thin or watery, let it simmer a few extra minutes so the layers stay hearty and not soggy.
- Keeping the casserole covered for the first part of baking helps everything heat through evenly, but uncovering it for the final 10 minutes gives you that bubbly, golden cheese topping everyone loves.
Substitutions and Variations for This Baked Spaghetti Casserole
How to Change the Protein in This Baked Spaghetti Casserole
The ground beef can be replaced with ground Italian sausage, either sweet or hot, and the result is excellent. If you use Italian sausage, taste the meat sauce before adding any additional Italian seasoning since the sausage is already well-seasoned and you may not need it. A combination of half ground beef and half Italian sausage gives you the fat and depth of beef with the fennel and herb notes from the sausage, which is a very good combination for this casserole. Ground turkey works for a leaner version, but add a tablespoon of Worcestershire sauce with the tomato paste to compensate for the lower fat content and milder flavor.
Best Pasta Substitutes for This Alfredo Spaghetti Bake
The spaghetti can be swapped for any pasta that holds up well in a bake. Fettuccine is the closest substitute and behaves almost identically. Rigatoni and penne both work for a shorter, more scoopable casserole that is easier to serve at a buffet or potluck. Linguine is a fine alternative if that is what you have. Avoid angel hair and other very thin pastas — they will overcook and clump in the oven before the rest of the dish is done.
How to Lighten the Alfredo Sauce in This Spaghetti Bake
For a lighter Alfredo, reduce the heavy cream to one cup and increase the milk to one cup. The sauce will be slightly less rich but will still hold together because of the roux. Do not try to substitute half-and-half for all of the heavy cream without increasing the flour, because the lower fat content means the sauce will be too thin to stay emulsified through the bake. Whole milk requires even more adjustment — increase the flour to two tablespoons and simmer the sauce longer before adding the cheese.
How to Make This Baked Spaghetti Casserole a Rosé Sauce Version
If you do not cook with alcohol, replace the red wine with beef broth. Adding a tablespoon of Worcestershire sauce with the broth gives you back some of the depth and umami that red wine contributes to the meat sauce.
Try It as a Rosé Sauce Casserole
The red and white sauce combination in this recipe is sometimes called a rose or pink sauce when the two are fully blended together. If you prefer that version, toss the pasta with the Alfredo, add about half the meat sauce, stir everything together, spread it in the baking dish, pour the remaining meat sauce on top, and proceed with the cheese and bake. The layered version gives you distinct textural contrast in every bite. The blended version gives you a more uniform, rosé pasta character throughout. Both are genuinely good.
Make Ahead and Storage Tips for This Alfredo Spaghetti Bake
This is one of the best make-ahead baked pasta dishes you can have in your rotation. You can fully assemble the casserole — Alfredo pasta layer, meat sauce layer, cheese on top — cover it tightly with plastic wrap, and refrigerate it for up to two days before baking. When you are ready to cook it, pull the dish out of the refrigerator about 30 minutes before it goes in the oven so it is not ice cold all the way through, then bake as directed and add about 10 extra minutes to the covered portion to account for the cold start.
Leftovers keep very well. Store them in an airtight container in the refrigerator for up to four days. To reheat individual portions, add a small splash of water, milk, or chicken broth to the container, cover loosely with a damp paper towel, and microwave in 90-second intervals until heated through. The liquid prevents the pasta from drying out and the Alfredo from getting gluey. For larger portions, cover with foil and reheat in a 325-degree oven for about 20 minutes.
How to Freeze This Spaghetti Casserole
To freeze, bake the casserole fully first, let it cool completely to room temperature, and then portion it into airtight freezer-safe containers for up to three months. Thaw overnight in the refrigerator and reheat in a covered dish at 325 degrees until the center is hot. Cream-based sauces can lose some of their creaminess through the freeze-thaw cycle, but the roux in this Alfredo gives it enough structure to hold much better than a roux-free version would. The texture after reheating from frozen is very good, not quite the same as fresh but absolutely satisfying.
What to Serve with This Baked Spaghetti with Alfredo Sauce
This is a rich, substantial dish, and the sides that work best alongside it are ones that provide contrast rather than adding more richness to the plate. A simple green salad dressed with a sharp red wine vinaigrette does exactly what the balsamic in the meat sauce does — it introduces acidity that makes the whole meal feel lighter and more balanced than it would without it. A cucumber and tomato salad with a little red onion, fresh basil, and a drizzle of olive oil is another excellent option, especially in summer when those vegetables are at their best.
Garlic bread is traditional and people will want it, but if you want to be slightly more considered about it, try baguette slices brushed with good olive oil instead of butter and toasted under the broiler. The olive oil version is less rich than butter-based garlic bread and provides a better textural contrast to the creamy pasta.
For a vegetable side that holds its own next to the casserole without competing with it, roasted zucchini, asparagus, or broccoli tossed in olive oil and salt and roasted at 425 degrees for 20 minutes is simple, fast, and genuinely good. The high-heat roasting gives those vegetables a little char and sweetness that works well against the richness of the casserole.
Frequently Asked Questions About Baked Spaghetti with Alfredo Sauce
Regular baked spaghetti is typically made with a tomato-based meat sauce layered over pasta, similar to a simplified lasagna. Baked spaghetti with Alfredo sauce, which is the dish that went viral on TikTok, adds a second layer of creaminess by tossing the pasta in a homemade Alfredo sauce before layering the meat sauce on top. The result is a casserole with two distinct sauce layers — creamy white underneath, savory red on top — bound together by melted mozzarella.
This is the most common problem with this recipe and it almost always comes down to one of two things: either you used jarred Alfredo sauce, which is not formulated to withstand oven heat, or your homemade Alfredo did not have a roux to stabilize it. A roux — butter and flour cooked together before the cream goes in — creates a starch-bound emulsion that stays together under oven heat. Without it, the fat in the cream sauce and the liquid separate when exposed to prolonged heat. The recipe above includes a roux specifically to solve this problem.
A watery casserole has three common causes. First, the meat sauce was not reduced enough before assembly — it should be thick, almost jammy, not pourable. Second, the pasta was not drained thoroughly enough before going into the dish. Third, too much Alfredo sauce was used relative to the amount of pasta, causing excess liquid to pool during baking. Simmer your meat sauce until it clearly thickens, drain your pasta well, and toss it with butter and pasta water rather than extra sauce.
You can, and many popular versions of this recipe do. Jarred Alfredo will save you time but it will separate in the oven to some degree regardless of brand, because the stabilizers used in commercial Alfredo are not designed for sustained oven heat. If you use a jar, reduce the bake time slightly and do not expect the creamy layer to hold together as cleanly as the homemade version does. The homemade Alfredo in this recipe takes about 10 extra minutes and the result is significantly better.
Yes, and it is actually one of the better make-ahead casseroles for a busy week. Assemble it completely, cover tightly with plastic wrap, and refrigerate for up to two days. Let it sit at room temperature for 30 minutes before baking, then add about 10 minutes to the covered baking time since it is starting cold from the refrigerator.
Both are layered, baked spaghetti casseroles and they are closely related. The key difference is the creamy element. This dish uses Alfredo sauce — butter, cream, and Parmesan — for the creamy pasta layer, which produces a lighter, silkier base that is easier to scoop. Million Dollar Spaghetti typically uses a mixture of cream cheese, sour cream, or ricotta layered into the pasta, which creates a denser, richer, more lasagna-like structure. If you want something that scoops cleanly and feels a little lighter, the Alfredo version is the one. If you want something ultra-dense and indulgent, Million Dollar Spaghetti leans that direction.
Yes. Bake the casserole fully, let it cool completely, and then freeze in portions in airtight containers for up to three months. Thaw overnight in the refrigerator and reheat covered at 325 degrees until hot through. The roux in the Alfredo gives the sauce enough structure to hold reasonably well through the freeze-thaw cycle. Expect the texture to be very slightly less silky than fresh but still excellent.
Yes with two adjustments. Use your preferred gluten-free spaghetti and cook it an extra minute under the package directions since gluten-free pastas tend to soften faster during baking. In the Alfredo, substitute the tablespoon of all-purpose flour with one teaspoon of cornstarch whisked into the cold milk before it goes into the pan. Also check your jarred spaghetti sauce label, as some brands use wheat as a thickener.
Almost always, this is caused by one of two things: using pre-grated Parmesan from a bag, which contains anti-caking agents that prevent clean melting, or adding the cheese to a sauce that is too hot. Use only freshly grated Parmesan from a block, reduce the heat to its lowest setting before adding it, and add it in small handfuls rather than all at once. If you are already seeing a grainy sauce developing, take the pan off the heat completely, add a tablespoon of warm pasta water, and whisk vigorously until it comes back together.
You can reduce the richness by using one cup of heavy cream and one cup of whole milk, which the recipe already does for balance. If you want to go further, using all whole milk requires increasing the flour to two tablespoons and simmering the sauce longer to achieve enough thickness. Half-and-half works but requires increasing the flour to about one and a half tablespoons. Avoid non-dairy milks for this application — their fat content and protein structure are too different to produce a reliable baked Alfredo sauce.
Looking for more pasta dinners? Try these!
Creamy Chicken Fettuccine Pasta
This creamy chicken fettuccine pasta is rich, comforting, and packed with tender chicken and silky sauce tossed with perfectly cooked pasta for an easy family dinner.
Simple Creamy Garlic Parmesan Chicken Pasta
Loaded with garlic, Parmesan, and juicy chicken, this creamy pasta recipe comes together quickly for a cozy weeknight meal everyone will love.
This one-pot beef taco pasta combines seasoned ground beef, tender pasta, and cheesy taco flavors in an easy dinner recipe with minimal cleanup.
Bright lemon, garlic, and juicy shrimp come together in this light and flavorful pasta dish that feels restaurant-worthy but is simple enough for busy nights.
Final Thoughts
Baked spaghetti with Alfredo sauce is genuinely one of the best comfort food casseroles in the current recipe landscape, and it deserves to be made properly. The viral version that spread across TikTok is good, but it is a starting point, not a finished recipe. When you take the extra two minutes to cook the tomato paste, the extra minute to build the roux, and the extra 30 seconds to finish the sauce with balsamic vinegar, you end up with a casserole that has actual depth and balance rather than just richness. The people in your house will not necessarily be able to articulate what is different about it. They will just ask you to make it again.
Baked Spaghetti with Alfredo Sauce (The Viral TikTok Casserole, Made From Scratch)
Equipment
Ingredients
Red Sauce
- 2 tablespoons olive oil
- 1 cup onion chopped
- ½ cup green bell pepper chopped
- 1 tablespoon garlic minced
- 1 pound ground beef 80/20
- 2 tablespoons tomato paste
- ¼ cup red wine or beef broth
- 1½ teaspoons salt
- ⅔ teaspoon black pepper
- 1 tablespoon Italian seasoning
- ½ teaspoon red pepper flakes optional
- 1½ (24-ounce jars) spaghetti sauce
- ½ teaspoon sugar
- ½ teaspoon balsamic vinegar finish
Pasta
- 1 pound spaghetti
- 1 tablespoon salt for water
- 1 tablespoon butter
- ¼ cup reserved pasta water
Creamy Alfredo Layer
- ½ cup butter
- 4 cloves garlic minced
- 1 tablespoon flour
- 1½ cups heavy cream
- ½ cup milk
- 1½ cups Parmesan freshly grated
- 1 ounce cream cheese optional, but recommended
- Pinch nutmeg
Cheese Layer
- 2 cups mozzarella shredded (divided)
- ½ cup provolone or fontina optional, for better melt and flavor
Instructions
- Make the Meat Sauce: Cook the onion and bell pepper in olive oil until softened. Add garlic and cook briefly, then brown the ground beef. Drain most of the grease, leaving a little in the pan. Stir in the tomato paste and cook for 2–3 minutes until darkened and caramelized. Add the wine or broth, scraping up any browned bits. Stir in the seasonings and spaghetti sauce, then simmer 10–15 minutes until thickened. Finish with sugar or grated carrot and balsamic vinegar.
- Cook the Pasta: Boil the spaghetti in salted water until just al dente, about 2 minutes less than package directions. Reserve 1/4 cup pasta water, then drain. Toss the pasta with butter and reserved pasta water until coated.
- Make the Alfredo Sauce: Melt butter in a saucepan and cook the garlic until fragrant. Whisk in the flour and cook for 1 minute. Slowly whisk in the cream and milk, then simmer until slightly thickened. Reduce heat to low and stir in the Parmesan gradually until melted and smooth. Stir in cream cheese if using, then season with nutmeg and salt.
- Combine Pasta and Alfredo: Pour the Alfredo sauce over the spaghetti and toss until evenly coated. Fold in 1 cup of mozzarella cheese.
- Assemble the Casserole: Preheat the oven to 350°F and grease a 9×13-inch baking dish. Spread the Alfredo spaghetti evenly into the dish, then top with the meat sauce. Sprinkle with the remaining mozzarella and provolone or fontina cheese.
- Bake and Serve: Cover with foil and bake for 20 minutes. Remove the foil and bake another 10 minutes until the cheese is melted and bubbly. Broil for 2–3 minutes if desired for extra color. Let the casserole rest for 5–10 minutes before serving.
