4 cups shredded zucchini (leave the skin on and use the small holes of the grater)
2 ½ cups all purpose flour
1/2 cup natural unsweetened cocoa powder
2 teaspoons baking soda
1/2 teaspoon salt
1 teaspoon cinnamon
1/2 teaspoon allspice
1 ½ cups granulated white sugar
2 large eggs
3/4 cup unsalted butter (12 tablespoons or 1 ½ sticks), melted
1/2 teaspoon espresso powder
2 teaspoons vanilla extract
1 cup semisweet chocolate chips
Preheat the oven to 350 degrees F. Grease bottom and sides of two 9 x 5-inch loaf pans; dust with flour, tapping out excess.
Place the freshly grated zucchini in a fine mesh strainer over a bowl to drain excess liquid while you prepare the rest of the ingredients.
In a medium bowl, whisk together the flour, cocoa, baking soda, salt, cinnamon and allspice; set aside.
In the bowl of a stand mixer fitted with the paddle attachment, beat together the sugar and eggs until smooth, about a minute. Add the melted butter, espresso powder and vanilla extract and beat until smooth, about 30 seconds. With a rubber spatula, fold in the shredded zucchini. Add the flour to the zucchini mixture in 3 additions, stirring until just combined after each addition. Fold in chocolate chips.
Divide the batter between the two prepared loaf pans, smoothing the top. Bake 50 to 55 minutes, or until a toothpick inserted in the center of the loaf comes out clean. Let cool in the pans for 5 minutes before removing loaf to a wire rack to cool completely.