Preheat the oven to 375℉/190℃. Line a muffin tin with liners and set aside. Mash the bananas.
In a bowl, add the flour, baking soda, baking powder, cornstarch, cinnamon, cloves, nutmeg, and salt. Stir to combine and set aside.
2 cups all-purpose flour, 1 tsp baking soda, 2 tsp baking powder, 1 tsp cinnamon, 1/8 tsp cloves, 1/8 tsp nutmeg, 2 tsp cornstarch, 1/4 tsp salt
In a bowl, add the mashed bananas, brown sugar, oil, eggs, vanilla, peanut butter, and sour cream. Whisk well to combine.
1 1/4 cups bananas, 3/4 cups creamy peanut butter, 3/4 cups dark brown sugar, 2 large eggs, 1 tbsp vanilla, 1/2 cup sour cream, 1/2 cup oil
Add in the dry ingredients and gently fold just until a soft muffin batter forms. Do not over-mix.
Scoop and divide the batter evenly between the liners, filling them all the way to the top.
Bake for 23-30 minutes, or until a toothpick inserted in the middle comes out clean.
Allow to cool, and enjoy!