01 -  Preheat oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners or lightly grease each cavity. 
 02 -  In a large mixing bowl, whisk mashed bananas, eggs, peanut butter, honey or maple syrup, applesauce, milk, and vanilla extract until thoroughly blended. 
 03 -  In a separate bowl, stir together rolled oats, whole wheat flour, baking powder, baking soda, salt, and cinnamon. 
 04 -  Add dry mixture to the wet ingredient bowl and gently fold until just combined. Avoid overmixing to maintain a tender muffin texture. 
 05 -  Fold in mini chocolate chips or chopped nuts if desired, distributing evenly throughout the batter. 
 06 -  Divide batter evenly among the muffin tin compartments, filling each about three-quarters full. Transfer to the oven and bake for 18 to 22 minutes, or until a toothpick inserted at the center emerges clean. 
 07 -  Cool muffins in the tin for 5 minutes, then remove and place on a wire rack to cool completely before serving.