Preheat oven to 350F and line a muffin tin with liners. Spray liners with non-stick spray as well.
In a large bowl, mash two bananas very well until no lumps remain.
Whisk in egg, maple syrup, and vanilla. Set aside.
In a smaller bowl, mix together oat flour, protein powder, baking powder, baking soda, and salt.
Add the dry ingredients to the wet ingredients and stir until combined.
Fold in chocolate chips.
Scoop into muffin tins until about ¾ full. I like to use a cookie scoop to make this easy! If you are adding more chocolate chips on top, add them now.
Bake at 350F for 15 minutes or until toothpick inserted in the middle comes out clean.
Store on counter or in fridge for up to 5 days. Freeze for longer.