01 - Preheat oven to 350°F (175°C). Line a standard 12-cup muffin tin with paper liners or lightly grease each cup.
02 - Combine mashed bananas, eggs, peanut butter, honey or maple syrup, applesauce, milk, and vanilla extract in a large mixing bowl. Whisk until smooth and fully incorporated.
03 - In a separate bowl, stir together rolled oats, whole wheat flour, baking powder, baking soda, salt, and ground cinnamon until evenly distributed.
04 - Add the dry ingredients to the wet ingredients and mix gently, stirring just until combined. Avoid overmixing to ensure light texture.
05 - Gently fold in chocolate chips or chopped nuts if using, ensuring even distribution throughout the batter.
06 - Divide batter evenly among the muffin cups, filling each about three-quarters full for optimal rise.
07 - Bake for 18 to 22 minutes, or until a toothpick inserted into the center of a muffin emerges clean.
08 - Allow muffins to cool in the tin for 5 minutes, then transfer to a wire rack to cool completely before serving.