01 - Preheat the oven to 350°F. Line a 9 x 5 inch loaf pan with parchment paper.
02 - In a large mixing bowl, mash the bananas thoroughly until smooth. Whisk in the eggs, applesauce, maple syrup, and vanilla extract until well combined.
03 - In a separate medium bowl, combine the oat flour, protein powder, baking soda, baking powder, cinnamon, and salt. Mix well to distribute evenly.
04 - Gently fold the dry ingredients into the wet mixture until just combined. Be careful not to overmix as this can result in a dense bread.
05 - Stir in the nuts or chocolate chips if using.
06 - Pour the batter into the prepared loaf pan and smooth the top with a spatula.
07 - Bake for 45 to 55 minutes, or until a toothpick inserted in the center comes out clean.
08 - Let the bread cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before slicing.