Prep the pan and oven: Heat the oven to 350°F (175°C). Grease a 9x5-inch loaf pan and line it with a parchment sling for easy removal.

Grate the zucchini: Use the large holes of a box grater. Lightly blot the grated zucchini with paper towels if it seems very wet, but don’t squeeze it dry—you want some moisture.

Mix dry ingredients: In a medium bowl, whisk flour, baking soda, baking powder, salt, cinnamon, and nutmeg until evenly combined.

Mix wet ingredients: In a large bowl, whisk eggs, granulated sugar, brown sugar, oil, and vanilla until smooth and slightly thickened, about 30–45 seconds.

Combine batter: Add the dry mixture to the wet. Stir gently with a spatula until a few flour streaks remain. Fold in the grated zucchini and any mix-ins (nuts, chocolate chips, or raisins) just until blended. Do not overmix.

Fill the pan: Scrape the batter into the prepared loaf pan and smooth the top. If you like, sprinkle a teaspoon of coarse sugar on top for a light crunch.

Bake: Place on the center rack and bake for 50–60 minutes. Start checking at 48 minutes. The loaf is done when a toothpick inserted in the center comes out mostly clean with a few moist crumbs.

Cool properly: Let the bread cool in the pan for 10–15 minutes. Lift it out using the parchment and transfer to a wire rack. Cool at least 1 hour before slicing to set the crumb.

Slice and serve: Use a serrated knife for neat slices. Enjoy warm or at room temperature, plain or with a pat of butter or cream cheese.