Step 1
Preheat oven to 350 degrees F (175 degrees C). Grease a 9x5-inch loaf pan with cooking spray.
Step 2
Combine butter, brown sugar, 1 egg, sour cream, 1/4 cup white sugar, and vanilla extract in a large bowl; whisk until smooth. Mash in bananas using a fork. Whisk in 1 cup flour, baking soda, baking powder, and salt until just combined.
Step 3
Whisk cream cheese, 1 egg, 1/4 cup white sugar, and 3 tablespoons flour together in a separate bowl.
Step 4
Pour half of the banana mixture into the prepared loaf pan. Spread cream cheese mixture evenly on top. Pour remaining banana mixture over cream cheese mixture.
Step 5
Bake in the preheated oven until top is firm, about 50 minutes. Cool in the pan, about 5 minutes.