Preheat oven 350 degrees.
In the large bowl of a stand mixer combine sugar, oil, eggs, vanilla, and milk. Mix until combined.
In another bowl, stir together the flour, cocoa powder, baking powder, baking soda, salt and cinnamon.
Slowly add dry ingredients to wet ingredients and mix until combined.
Gently stir in zucchini.
Divide batter between two greased 9x5 loaf pans.
Bake at 350 degrees for 1 hour or until a toothpick comes out clean.
Cool on wire racks for about 10 mins. Then turn the breads out of the pans and cool completely on wire racks.