Preheat the oven to 350ºF. Coat a 9x11 baking dish with cooking spray.
In the bowl of a stand mixer fitted with the paddle attachment, combine sugar, oil, and flour until the mixture resembles wet sand. Turn the mixer to low and add cocoa, zucchini, vanilla, salt, and baking soda. Mix until well combined. Using a rubber spatula, stir in the chocolate chips.
Pour the batter into the prepared pan and bake for 25-30 minutes or until a toothpick inserted in the center comes out clean.
Remove from the oven and let cool on a wire rack. Cut into squares and serve.