Preheat oven to 350°F. Grease a 12-cup muffin tin.
In a large bowl, whisk together the flour, cocoa powder, baking soda, baking powder, and salt.
In a medium bowl, whisk together the sugar, oil, egg, and vanilla extract. Add the wet ingredients to the dry ingredients and stir until just combined.
Fold in the zucchini and chocolate chips.
Divide the batter evenly among the muffin cups. Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean.
Allow to cool before serving.
Interesting Facts
Zucchini is a type of summer squash.
Muffins are thought to have originated in England in the 1700s.