Follow these step-by-step instructions to create a delectable loaf of Zucchini Banana Bread:

1. Preheat Your Oven: Start by preheating your oven to 350°F (175°C). Grease a 9×5-inch loaf pan or line it with parchment paper for easy removal.
2. Prepare the Dry Ingredients: In a medium-sized bowl, whisk together the flour, baking soda, baking powder, salt, cinnamon, and nutmeg. Set aside.
3. Mix the Wet Ingredients: In a large mixing bowl, cream together the melted butter, granulated sugar, and brown sugar until well combined. Add the eggs, one at a time, beating well after each addition. Stir in the vanilla extract.
4. Combine Bananas and Zucchini: Fold in the mashed bananas and grated zucchini into the wet mixture, ensuring they are evenly distributed.
5. Combine Wet and Dry Ingredients: Gradually add the dry ingredient mixture to the wet mixture, stirring until just combined. Be careful not to overmix, as this can result in a dense loaf.
6. Add Nuts and Chocolate (Optional): If using, gently fold in the chopped walnuts or pecans and chocolate chips until evenly dispersed throughout the batter.
7. Pour into Loaf Pan: Pour the batter into the prepared loaf pan, smoothing the top with a spatula.
8. Bake: Place the loaf pan in the preheated oven and bake for 55-65 minutes, or until a toothpick inserted into the center comes out clean. If the top of the bread is browning too quickly, cover it loosely with aluminum foil.
9. Cool: Once baked, remove the bread from the oven and let it cool in the pan for about 10 minutes. Then, transfer it to a wire rack to cool completely before slicing.