Preheat oven to 350°.
Mix flour, baking powder, and baking soda together. Set aside.
Mash bananas in a stand mix (I use the paddle attachment to do this). Then stir in the sugars, egg, vanilla and melted butter.
Add the dry ingredients to the wet and stir until just combined.
Fold in the nuts and chocolate chips.
Line a muffin tin with cup cake wrappers. Fill with batter and bake for 20-25 minutes.