Step 1: Preheat your oven to 325°F (160°C). Grease and flour two 9x5-inch loaf pans. You can also line them with parchment paper for easier removal.
Step 2: In a large bowl, whisk together the flour, granulated sugar, baking soda, ground cinnamon, salt, and ground nutmeg until well combined.
Step 3: In a separate medium bowl, whisk together the eggs, vegetable oil, applesauce, and vanilla extract until smooth.
Step 4: Pour the wet ingredients into the dry ingredients. Stir with a spoon or spatula just until combined, being careful not to overmix.
Step 5: Gently fold in the grated zucchini until it is just incorporated into the batter. If adding optional mix-ins like chocolate chips or nuts, fold them in now.
Step 6: Divide the batter evenly between the two prepared loaf pans and spread gently to level the tops.
Step 7: Bake for 50-60 minutes, or until a wooden skewer or toothpick inserted into the center of the loaves comes out clean. Baking times may vary, so check for doneness around 50 minutes.
Step 8: Remove the loaves from the oven and let them cool in the pans for 10-15 minutes before inverting them onto a wire rack to cool completely.
Step 9: Allow the zucchini bread to cool completely before slicing for the best texture and flavor. Store cooled bread in an airtight container at room temperature for up to 3-4 days, or freeze for longer storage.