Preheat your oven to 350°F (175°C) and prepare your muffin tin by greasing it lightly or lining it with muffin liners.
In a large mixing bowl, combine the mashed bananas, shredded zucchini, creamy peanut butter, canola oil, egg, and vanilla extract. Whisk these ingredients together until they are well blended and smooth.
In another bowl, whisk together the whole wheat pastry flour, brown sugar, baking soda, and salt. Make sure there are no lumps in the flour mixture for an even texture.
Gradually add the dry ingredients to the wet ingredients, stirring gently until no dry flour remains. Be careful not to overmix; a few lumps are perfectly fine.
Gently fold in the chocolate chips into the batter, ensuring they are evenly distributed throughout.
Spoon the muffin batter into the prepared muffin tin, filling each cup about halfway. Then, add a heaping tablespoon of Nutella into the center of each muffin cup. Top with more batter until the cups are about 3/4 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 (except for melted chocolate).
Once baked, remove the muffins from the oven and let them cool in the tin for a few minutes before transferring them to a cooling rack. Enjoy warm or at room temperature!
