Preheat Oven: Preheat your oven to 350°F (175°C). Grease and flour a 9x5-inch loaf pan or line it with parchment paper.
Prepare Zucchini: Grate the zucchini and gently squeeze out excess moisture with a clean kitchen towel or paper towels. Set aside.
Mix Dry Ingredients: In a medium bowl, whisk together the flour, baking soda, baking powder, salt, cinnamon, and nutmeg (if using).
Mix Wet Ingredients: In a large mixing bowl, whisk together the eggs, vegetable oil, granulated sugar, brown sugar, and vanilla extract until smooth.
Combine Wet and Dry Ingredients: Gradually stir the dry ingredients into the wet mixture until just combined. Do not overmix. Fold in the grated zucchini, nuts, and raisins or chocolate chips (if using).
Pour into Pan: Pour the batter into the prepared loaf pan and smooth the top with a spatula.
Bake: Bake in the preheated oven for 50-60 minutes, or until a toothpick inserted into the center comes out clean.
Cool and Serve: Allow the zucchini bread to cool in the pan for 10 minutes before transferring to a wire rack to cool completely. Slice and serve.