Prepare the Baking Dish: Grease a 9x13-inch baking dish generously with butter or non-stick cooking spray.

Layer the Bread: Place half of the cubed French bread (approximately 6 cups) into the bottom of the prepared dish in an even layer.

Mix the Cheesecake Swirl: In a medium mixing bowl, beat the softened cream cheese, powdered sugar, 4 tablespoons of milk, and 2 teaspoons of vanilla extract until smooth.

Add the First Layer: Drop spoonfuls of half the cream cheese mixture over the bread cubes. In a separate small bowl, toss the blueberries with 4 tablespoons of sugar and 2 tablespoons of lemon juice. Scatter half of this berry mixture over the cream cheese.

Repeat Layers: Add the remaining bread cubes to the dish. Top with the remaining cream cheese mixture and the rest of the blueberries.

Whisk the Custard: In a large bowl, whisk together the 10 eggs, milk, heavy cream, cinnamon, nutmeg, 1 tablespoon of vanilla, and maple syrup until well combined.

Saturate the Bread: Slowly pour the custard mixture over the bread, ensuring all pieces are evenly coated.

The Soak: Cover the dish tightly with foil. For best results, refrigerate overnight (8–12 hours). If making the same day, allow the dish to sit for at least 30–45 minutes to allow the bread to absorb the custard.

Prepare the Streusel: Preheat the oven to 350°F. In a small bowl, combine the flour, brown sugar, and cinnamon. Use a fork or pastry cutter to cut in the cold, cubed butter until the mixture resembles coarse crumbs.

Bake: Sprinkle the streusel evenly over the top of the casserole. Bake uncovered for 45–55 minutes. The casserole is done when the center is set and the top is golden brown.

Rest and Serve: Allow the casserole to rest for 10 minutes before slicing to let the custard fully set. Serve warm with extra maple syrup if desired.