Preheat your oven to 350°F (175°C). Grease a 12-cup muffin tin or line with muffin liners.
In a large bowl, whisk together the flour, baking powder, baking soda, salt, cinnamon, and nutmeg.
In another bowl, beat together the sugar, oil, eggs, and vanilla extract until well combined.
Stir the wet ingredients into the dry ingredients until just combined. Do not overmix.
Fold in the grated zucchini.
Divide the batter evenly among the prepared muffin cups.
Bake for 20-25 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
Allow the muffins to cool in the tin for 5 minutes, then transfer to a wire rack to cool completely.