Preheat oven to 325° F. Line two 8x4-inch (or 9x5) loaf pans with parchment paper and set aside.
In a large bowl, whisk together the dry ingredients—flour, cinnamon, nutmeg, baking soda, baking powder and salt. Set aside.
In a separate large bowl using a hand mixer, beat together sugar, brown sugar and eggs until combined, about 1 minute. Add oil and vanilla, and beat again until incorporated, about 1 more minute.
Add dry ingredients to the wet mixture and use a wooden spoon or rubber spatula to stir until incorporated.
Stir grated zucchini into the mixture until evenly combined. Pour batter evenly into the two prepared pans. Bake for 50 to 60 minutes, or until tester inserted in the center comes out clean. Cool in pan on rack for 20 minutes. Remove bread from pan, and completely cool.
This recipe makes two loaves in 8x4-inch pan. Each loaf yields about 8 slices. This recipe can be cut in half (use 1 egg).
Vegetable oil substitute: Applesauce may be used as a substitute. I recommend 1/2 cup vegetable oil and 1/2 cup unsweetened applesauce.
Keep grated zucchini wet (do not pat dry with paper towel). Pack lightly in the measuring cup—it's okay if there's a little more than two cups!
Storing zucchini bread: Store cooled zucchini bread in an airtight container at room temperature for up to 3 days or in the refrigerator for up to 5 days.
Freezing zucchini bread: Wrap cooled loaf in plastic wrap and then aluminum foil. Store in the freezer for 2 to 3 months. Defrost in the refrigerator before cutting and serving at room temperature.