• Preheat the Oven: Preheat your oven to 350°F (175°C) and grease a 9x5-inch loaf pan with butter or cooking spray.

Prepare the Banana Bread Batter:

• In a large mixing bowl, mash the ripe bananas using a fork until smooth.
• Add the sugar, vanilla extract, eggs, melted butter, and sour cream to the mashed bananas. Stir well to combine.
• In a separate bowl, sift together the flour, baking powder, baking soda, cinnamon, and salt.
• Gradually add the dry ingredients to the wet ingredients, stirring until just combined. Be careful not to overmix, as this can result in a dense bread.

Prepare the Cream Cheese Swirl:

• In another mixing bowl, beat the room temperature cream cheese until smooth and creamy.
• Add the egg, sugar, and flour to the cream cheese, and beat until well combined and smooth.

Make the Cinnamon Crumble Topping:

• In a small bowl, combine the flour, sugar, melted butter, and cinnamon until crumbly. Set aside.

Assemble the Bread:

• Pour half of the banana bread batter into the prepared loaf pan, spreading it out evenly.
• Spoon the cream cheese mixture over the banana bread batter in the pan, then pour the remaining banana bread batter on top.
• Use a knife or skewer to gently swirl the cream cheese mixture into the banana bread batter, creating a marbled effect.
• Sprinkle the cinnamon crumble topping evenly over the top of the batter.

Bake the Banana Bread:

• Place the loaf pan in the preheated oven and bake for 50-60 minutes, or until a toothpick inserted into the center comes out clean.
• If the top of the bread starts to brown too quickly, loosely cover it with aluminum foil to prevent burning.

Cool and Serve:

• Once baked, remove the banana bread from the oven and allow it to cool in the pan for 10-15 minutes.
• Carefully transfer the bread to a wire rack to cool completely before slicing and serving.