01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners or lightly grease with cooking spray.
02 - In a large bowl, whisk together flour, baking powder, baking soda, salt, cinnamon, and nutmeg until well combined.
03 - In a separate medium bowl, beat eggs. Add oil, granulated sugar, brown sugar, and vanilla extract. Whisk until smooth and fully incorporated.
04 - Pour wet mixture into dry ingredients. Fold gently until just combined—do not overmix as this will result in dense muffins.
05 - Gently fold in grated zucchini and any optional add-ins such as nuts, chocolate chips, or raisins until evenly distributed.
06 - Divide batter evenly among prepared muffin cups, filling each about 3/4 full.
07 - Bake for 22 to 25 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
08 - Let muffins cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.