Preheat your oven to 350°F (175°C) and grease a 9x5 inch loaf pan or line it with parchment paper.
In a large mixing bowl, combine the grated zucchini with the granulated sugar and brown sugar. Allow it to sit for about 10 minutes to release its moisture.
Add the eggs, vegetable oil, and vanilla extract to the zucchini mixture. Whisk well until everything is combined.
In another bowl, whisk together the all-purpose flour, whole wheat flour, baking soda, baking powder, ground cinnamon, nutmeg, and salt.
Gradually add the dry ingredients to the wet ingredients, stirring just until combined; do not overmix. If using, fold in the chopped nuts and chocolate chips at this stage.
Pour the batter into the prepared loaf pan, smoothing the top with a spatula.
Bake for approximately 55-65 minutes or until a toothpick inserted into the center comes out clean.
Allow the bread to cool in the pan for about 10 minutes before transferring it to a wire rack to cool completely.
Notes
Optional ingredients can be adjusted based on preference.