Preheat oven to 350°F, line a muffin tin with paper liners, and set aside.
In a large bowl, stir together the flour, baking powder, cinnamon, and salt; set aside.
In a small bowl, whisk together the brown sugar, oil, granulated sugar, eggs, and vanilla.
Add the sugar mixture to the flour mixture and stir well.
Mixture will be very thick.
Add the zucchini to the batter, stirring well; the moisture will make the batter thinner.
Fold in the chocolate chips, reserving a few to decorate muffin tops if desired.
Divide the batter evenly between the 12 muffin liners, press the remaining chocolate chips on top, and then bake in preheated oven for 18–20 minutes or until a toothpick inserted into the center comes out clean.