Step 1: Preheat your oven to 375°F (190°C) and line a 12-cup muffin tin with paper liners or grease it thoroughly. This ensures your delicious healthy banana oat muffins won't stick.
Step 2: In a large mixing bowl, mash the ripe bananas until mostly smooth with a few lumps remaining for texture. Add the egg, applesauce (or yogurt), maple syrup (or honey), milk, and vanilla extract. Whisk these wet ingredients together until well combined.
Step 3: In a separate medium bowl, combine the whole wheat flour, rolled oats, baking powder, baking soda, cinnamon, and salt. Whisk briefly to distribute the leavening agents and spices evenly.
Step 4: Pour the dry ingredients into the wet ingredients. Using a spatula or wooden spoon, mix until just combined. Be careful not to overmix; a few lumps are perfectly fine for moist muffins. If using, gently fold in the chopped walnuts or chocolate chips at this stage.
Step 5: Divide the batter evenly among the 12 muffin cups. Sprinkle a few extra rolled oats on top of each muffin for a rustic look and added texture.
Step 6: Bake for 20-25 minutes, or until a wooden skewer inserted into the center of a muffin comes out clean. The tops should be golden brown and spring back when lightly touched.
Step 7: Remove the muffins from the oven and let them cool in the muffin tin for 5 minutes before transferring them to a wire rack to cool completely. Enjoy these warm or at room temperature as a perfect example of banana recipes healthy and delicious!