Start by washing and finely grating your zucchini. Make sure to squeeze out any excess moisture gently with a clean towel or paper towel.
In a medium-sized bowl, whisk together the granulated sugar, vegetable oil, eggs, and vanilla extract until the mixture is smooth and slightly fluffy.
In a separate bowl, sift together the all-purpose flour, cocoa powder, baking soda, baking powder, and salt.
Slowly add the dry ingredients to the wet ingredients, folding gently with a spatula until just combined. Next, fold in the grated zucchini and chocolate chips evenly.
Preheat your oven to 350°F (175°C). Grease an 8x8-inch baking pan or line it with parchment paper. Pour the batter into the pan, smoothing the surface with a spatula.
Bake for 30-35 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs attached.
Allow the cake to cool completely in the pan on a wire rack before slicing. Enjoy as is or with a light dusting of powdered sugar.