Pre-heat the oven to 350 F.
Spray an 8.5-inch x 4.5-inch x 3-inch loaf pan with floured cooking spray; alternatively, grease and flour the pan; set aside.
In a large bowl, add the egg, brown sugar, vegetable oil, sour cream and vanilla; whisk to combine.
Add the mashed bananas; mix together.
Add 1 cup all-purpose flour, baking powder, baking soda and a pinch of salt; stir gently with a spoon until just combined.
Spread half of the banana batter into the prepared loaf pan.
In a separate bowl, combine cream cheese ingredients; spread over mixture on top.
Top with remaining banana batter and smooth very lightly with a spatula as to not disturb cream cheese layer; gently push batter into corners and sides as necessary.
Place in the pre-heated oven and bake for about 35 to 40 minutes or until the top is domed, golden, the center is set and a toothpick inserted in the center comes out clean.
Remove from the oven, cool and serve.
