Heat the oven to 350 degrees F. Butter or spray the inside of a 9 x 5-inch inch loaf pan.
In a medium bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon and cloves, if using.
If adding walnuts and/or raisins to the bread, stir them into the dry mixture.
In another medium bowl, whisk together the eggs, oil, brown and granulated sugars and vanilla extract.
Stir in the zucchini.
Add the wet ingredients into the dry ingredients and mix just until combined.
Transfer the mixture to the prepared loaf pan. Bake for 55 to 60 minutes, until slight crumbs remain on a wooden pick when stuck into the middle of the loaf.
Let cool for 10 minutes in the pan, then remove and let cool completely on a wire rack before slicing.
Cover and store leftover the bread at room temperature for up to 3 to 4 days or in the refrigerator for up to 1 week.