Preheat your oven to 350°F (175°C) and grease a 9x13 inch baking pan with butter or cooking spray.

In a mixing bowl, sift together 1 ¾ cups of all-purpose flour, ¾ cup of unsweetened cocoa powder, 1 teaspoon of baking soda, 1 teaspoon of baking powder, ½ teaspoon of salt, and 1 teaspoon of ground cinnamon.

Cream together ½ cup of softened unsalted butter, ½ cup of vegetable oil, and 1 ¾ cups of granulated sugar until light and fluffy, about 3-4 minutes.

Add 2 large eggs one at a time into the butter mixture, mixing well after each addition, then stir in 2 teaspoons of pure vanilla extract.

Gradually mix the dry ingredients into the wet mixture, alternating with 1 cup of buttermilk, starting and ending with the flour mixture.

Gently fold in 1 cup of finely grated zucchini and 1 cup of semi-sweet chocolate chips using a spatula.

Pour the batter into the prepared baking pan and spread it evenly.

Bake the cake for 45-50 minutes, checking for doneness with a toothpick.

Once baked, let the cake cool in the pan for about 10 minutes before transferring to a wire rack to cool completely.

Slice the cooled cake into squares and serve plain or with optional toppings like powdered sugar, whipped cream, or fresh berries.