Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan or line it with parchment paper.

In a large bowl, combine the grated zucchini with the gluten-free flour, baking powder, baking soda, salt, cinnamon, and nutmeg. Stir until well mixed.

In another bowl, whisk together the granulated sugar, brown sugar, vegetable oil, eggs, and vanilla extract until smooth and well combined.

Pour the wet ingredients into the dry ingredients and stir until just combined. Be careful not to overmix.

Fold in the walnuts or pecans and raisins or chocolate chips if using.

Pour the batter into the prepared loaf pan and spread it evenly.

Bake in the preheated oven for 50-60 minutes or until a toothpick inserted into the center comes out clean.

Allow the zucchini bread to cool in the pan for about 10 minutes before transferring it to a wire rack to cool completely.

Slice and serve. Enjoy your delicious gluten-free zucchini bread!