Preheat oven to 350 degrees and grease two 9×5 inch loaf pans.
In a large bowl, whisk together the melted butter and 6 tablespoons cocoa powder. Whisk in sugar, brown sugar, coconut oil, and vanilla until well combined. Add zucchini and mix well.
In a medium bowl, mix together the remaining 3 Tbsp cocoa powder, flour, baking soda, salt, and cinnamon. Stir chocolate chips into the flour mixture.
Add the flour mixture to the large bowl and fold together to combine. Pour evenly into the two loaf pans.
Bake for 60-65 minutes, or until a toothpick inserted in the center of the bread comes out clean.