Best Yet Banana Mini Muffins

Preheat oven to 375 degrees F (190 degrees C). Grease 2 mini muffin tins with cooking spray. Combine flour, baking powder, and baking soda in a bowl. Blend bananas, sugar, butter, and egg together in a separate bowl. Add to flour mixture; stir batter well to combine. Scoop batter into prepared muffin tins, filling each cup 2/3 of the way full. Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 15 minutes.