Preheat oven to 350°F.
Grease a 9x5 inch loaf pan or line it with parchment paper.
In a large mixing bowl, whisk together the sugar, oil, eggs, and vanilla until smooth.
Stir in the grated zucchini.
In a separate bowl, combine the flour, cocoa powder, baking powder, baking soda, salt, and cinnamon.
Add the dry ingredients to the wet ingredients and stir until just combined.
Fold in the chocolate chips and any optional add-ins like nuts or coconut.
Pour the batter into the prepared loaf pan and spread it evenly.
Bake for 50 to 60 minutes, or until a toothpick inserted in the center comes out clean or with just a few moist crumbs.
Let the bread cool in the pan for 10 minutes.
Carefully remove it from the pan and transfer to a wire rack to cool completely before slicing.