1. Preheat oven to 375°F; mist a standard 12-cup muffin tin with cooking spray or line with paper or foil liners. In a large bowl, combine both types of flour with baking powder, cinnamon and salt.
2. In a separate bowl, mix bananas with eggs, sugar, milk, butter and vanilla. Whisk until smooth. Fold banana mixture into flour mixture just until combined and batter forms; do not overmix.
3. Spoon batter into muffin cups; place a banana chip on top of each one, if desired. Bake until a toothpick inserted into center of a muffin comes out clean, 18 to 20 minutes. Let cool in pan on a wire rack for 10 minutes, then turn out onto rack to cool completely.