Wash your hands well with soap and warm water for at least 20 seconds.
Peel bananas and add to a medium mixing bowl. Mash bananas with a fork.
Add applesauce, sour cream, vanilla, and egg and beat mixture with whisk or fork until smooth.
In a separate medium mixing bowl, add flour, baking powder, baking soda, and salt and mix well.
Coat 12 cup muffin pan with vegetable spray oil.
Add wet ingredients to flour mixture and mix until combined. Fill each muffin cup about 2/3 full. Place muffin pan in oven and bake for 20 minutes or until toothpick inserted in the center of a muffin comes out clean.