Preheat your oven to 350°F (175°C) to ensure that your muffins will bake evenly.
Lightly grease your muffin tin with cooking spray or line it with muffin liners for easy removal.
In a large mixing bowl, whisk together the whole wheat pastry flour, sugar, cocoa powder, salt, and baking soda until well combined.
In another bowl, mix the mashed bananas, unsweetened applesauce, egg, and vanilla extract until smooth and creamy.
Pour the wet ingredients into the dry ingredients. Gently fold them together using a rubber spatula, being careful not to overmix.
Scoop the batter into the prepared muffin tin, filling each cup about two-thirds full.
Place the muffin tin in the preheated oven and bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean.
Once baked, remove the muffins from the oven and let them cool in the tin for a few minutes. Then, transfer them to a cooling rack to cool completely.
