Divide the batter among the prepared muffins tins.
Sprinkle with coarse sugar.
Bake for 5 minutes at 425°F; then, without opening the oven, reduce heat to 350°F and continue baking for another 10–15 minutes, or until a toothpick inserted in the center comes out clean.
Let the muffins cool for 5 minutes in the muffin pan, and then remove to a wire rack to finish cooling.
Notes
Oil: I like to bake with a neutral oil like light olive oil. You could also use canola oil or vegetable oil.
Brown sugar: Feel free to use dark brown sugar if you prefer.
Zucchini: I don't peel the zucchini, and I shred them with the larger hold on the box grater.
Flour: To properly measure the flour, you can weigh it, or sift, lightly spoon into the measuring cup, and then level. For the weights, simply click "metric" just above the ingredients.