Preheat to 325° F.
Generously grease or spray a standard size loaf pan and set aside
In a large mixing bowl, add the eggs, brown sugar, vegetable oil, cocoa powder, salt, vanilla extract, and cinnamon. Whisk until completely blended. Stir in the baking powder and baking soda and mix well.
Add the flour, grated zucchini, and chocolate chips and mix well with a wooden spoon or spatula. Pour the batter into the loaf pan.
Bake zucchini bread, for about an hour to an hour ten, or until a tester inserted into the center comes out clean. Transfer to a wire rack and let bread cool in the pan before serving.