Preheat oven to 350 degrees F. Grease an 9x13 baking pan with cooking spray, set aside.
In a stand mixer, combine sugar, oil, and flour, combine until mixture resembles wet sand. It will be dry looking and that is ok. While mixing, on low, add cocoa, shredded zucchini, vanilla extract, salt and baking soda. Mix until well combined. The mixture will moisten once the zucchini is added. Stir in one cup of the chocolate chips.
Pour brownie batter into prepared pan and sprinkle with remaining chocolate chips. Bake for 28-32 minutes or until a toothpick comes out clean and the brownies are set.
Cool completely on a wire rack. Cut brownies into squares and serve.
Notes
Store the brownies on the counter for up to 3 days. You can also freeze the brownies for up to 3 months.