Prepare the Muffin Batter:
Preheat your oven to 350°F (175°C) and line a muffin tin with paper liners or grease it with non-stick spray.
In a medium bowl, whisk together the flour, baking soda, and salt.
In a separate bowl, mix the granulated sugar, brown sugar, and melted butter until smooth.
Beat in the eggs and vanilla extract, then stir in the mashed bananas.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Make the Cream Cheese Filling:
In a bowl, beat the cream cheese, granulated sugar, egg yolk, and vanilla extract until smooth and creamy.
Assemble the Muffins:
Using a scoop or spoon, fill each muffin liner halfway with the banana batter.
Add a dollop of the cream cheese mixture to the center of each muffin.
Top with another spoonful of banana batter, covering the cream cheese filling.
Bake:
Bake in the preheated oven for 18–22 minutes, or until a toothpick inserted into the muffin (avoiding the cream cheese center) comes out clean.
Let the muffins cool in the tin for 5 minutes before transferring them to a wire rack to cool completely.