Preheat your oven to 350°F (175°C). Grease a 9×5 inch loaf pan with cooking spray.
In a large mixing bowl, whisk together the mashed bananas, eggs, vegetable oil, applesauce, and vanilla extract.
2 banana, 2 egg, 1/4 cup vegetable oil, 1/4 cup apple sauce, 1 tsp vanilla extract
In a separate bowl, whisk together the whole wheat flour, baking soda, cinnamon, and salt.
1 1/2 cups whole wheat flour, 1 tsp baking soda, 1/2 tsp cinnamon, 1/4 tsp salt
Add the dry ingredients to the wet ingredients and stir until just combined. Fold in the chopped walnuts, if using.
1/4 cup walnuts
Pour the batter into the prepared loaf pan and bake for 50-60 minutes or until a toothpick inserted into the center comes out clean.
Let the banana bread cool in the pan for 10 minutes before removing it to a wire rack to cool completely.