Preheat oven to 350 degrees Fahrenheit. Line or grease a muffin pan and set aside.
In a large bowl, whisk together four, cocoa powder, granulated sugar, brown sugar, salt, baking powder, and baking soda.
Add milk, oil, eggs, and vanilla extract. Stir until just combined. Fold in zucchini and 1 cup of the chocolate chips.
Fill each muffin cup 3/4 full. Top with the remaining chocolate chips on each muffin.
Bake for 17-20 minutes or until a toothpick inserted into the center of each muffin comes out clean. Allow muffins to cool for 5 minutes before transferring to a cooling rack to finish cooling. Enjoy!