Prep the pan and oven: Heat the oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners or lightly grease with oil.
Mash and mix the wet ingredients: In a large bowl, mash the bananas until mostly smooth.
Whisk in eggs, maple syrup, oil, almond milk, and vanilla until combined.
Whisk the dry ingredients: In a separate bowl, whisk oat flour, almond flour, protein powder, baking powder, baking soda, salt, and cinnamon.
Combine gently: Add dry ingredients to wet. Stir with a spatula just until no dry streaks remain. The batter should be thick but scoopable.
If it’s too thick, add 1–2 tablespoons more milk.
Fold in mix-ins: Stir in chocolate chips, berries, or nuts. Avoid overmixing to keep muffins tender.
Fill the cups: Divide batter evenly among the 12 cups, about 3/4 full. Smooth the tops for even baking.
Bake: Bake 18–22 minutes, or until tops are set and a toothpick comes out with a few moist crumbs but no wet batter.
Cool: Let muffins cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.
This helps them set and prevents soggy bottoms.
Enjoy: Eat warm or at room temperature. Add a smear of almond butter for extra protein and healthy fats.