Grease and flour a 9x12 pan, then preheat oven to 325-degrees F.
Soften butter in the microwave.
1 stick butter
Add the dry ingredients to a large bowl.
2½ cups all-purpose flour, 1 teaspoon baking soda, ½ teaspoon baking powder, ½ teaspoon salt, ¼ cup cocoa powder, 1 teaspoon cinnamon, 1¾ cups sugar
Grate the zucchini into a medium bowl.
2 cups zucchini
Crack and gently whisk eggs into a separate bowl. Do not beat.
2 eggs
Add the softened butter, eggs and the rest of the wet ingredients (except for the chocolate chips and walnuts if you are using them) to the dry ingredients.
½ cup vegetable oil, 3 teaspoons vanilla, ½ cup buttermilk
Pour the batter into the prepared pan and sprinkle the chocolate chips and walnuts on top if you want.
½ cup semi-sweet chocolate bits, ½ cup chopped walnuts
Bake 45 minutes until toothpick comes out clean.