Preheat oven to 325º F. Prepare a loaf pan with butter or shortening and lightly flouring. Set aside. Cream together coconut oil and sugars until well combined. Add eggs one at a time, making sure well combined before adding the next. Add flour, cocoa powder, salt, baking soda, baking powder, and espresso powder and slowly combine with egg mixture. Stir in grated zucchini, vanilla and chocolate chips, if using.
Pour batter into prepared loaf pan and bake until a toothpick comes out clean when inserted in the center, about 1 hour. Allow bread to cool in the pan for about five minutes before turning out onto a serving tray.
Store under a cake dome or in an airtight container. Freezes well.