Whisk dry ingredients: In another bowl, whisk flour, baking soda, baking powder, salt, cinnamon, and nutmeg.
Combine wet and dry mixtures, stirring gently until just combined.
Add optional nuts, folding them into the batter gently.
Pour the batter into the prepared loaf pan.
Bake for 50-60 minutes or until a toothpick comes out clean.
Cool the bread in the pan for 10 minutes before transferring to a wire rack.
Notes
Make sure the zucchini is well-drained to prevent extra moisture in the batter. Feel free to experiment with add-ins like chocolate chips or dried fruits.