Preheat oven to 350 degrees F. Line 12 muffin tin with parchment paper muffin liners and spray with cooking spray. Set aside. In a large bowl, add bananas and mash with a fork.
Add egg, maple syrup, peanut butter, vanilla extract, cinnamon, baking powder, baking soda and protein powder. Whisk very well until combined and no lumps.
Add almond flour and oat flour (make sure to level the top with a knife and do not pack) and stir with spatula until well mixed.
Garnish with strawberries and chocolate chips, stir a few times until just incorporated.
Using an ice cream scoop, divide batter between 12 openings of previously prepared muffin tin, about 3/4 full per each.
Add strawberries and chocolate chips on top, and bake for 22 minutes or until toothpick inserted in the center comes out clean. Don't overbake.
Remove from the oven, let cool for 15 minutes and enjoy.
Notes
Store: Store muffins at room temperature for 1 day and then transfer to refrigerator for another 4 days.
Freeze: Freeze in a large freezer bag for up to 3 months.
Ripe bananas: You can use yellow ripe or just ripe bananas, add a few more tablespoons of maple syrup.
Warmed up peanut butter: If you keep your peanut butter refrigerated or it's thick, warm it up in the microwave or on the stove until it's runny. Any other nut/seed butter works.
Vegan: Use 1/2 cup of flavorite flavored plant-based protein powder, reduce maple syrup to 2 tbsp and add 1/2 cup any milk or water to the batter. Replace egg with a flax egg.
Mini chocolate chips: Mini chocolate chips will distribute more evenly among the muffins because the amount is small.
Almond and oat flours: I have not tried any other flours, so can't recommend. You will need different amount though because all flour act differently. Baking is a science and it's best to follow the recipe.
Berries: Raspberries, blackberries, or blueberries would all work!