Preheat your oven to 350°F (175°C).
Prepare Ramekin: Lightly grease a single-serve ramekin with non-stick spray or a small amount of butter.
Mix Wet Ingredients: In a small bowl, mash the banana until smooth. Add the milk, maple syrup (if using), and vanilla extract. Stir well.
Combine Dry Ingredients: In another bowl, mix the rolled oats, protein powder, baking powder, cinnamon, and salt.
Combine Wet and Dry Ingredients: Add the dry ingredients to the wet mixture and stir until fully incorporated. The batter will be slightly thick.
Pour Into Ramekin: Spoon the batter into the prepared ramekin and spread it out evenly. Top with chocolate chips or nuts if desired.
Bake: Bake in the preheated oven for 18–22 minutes, or until the top is firm and golden.
Cool and Enjoy: Let it cool for a few minutes before digging in. Enjoy warm for a quick, protein-packed snack or breakfast!