Preheat oven to 350°F. Grease a 9x5-inch loaf pan.
In a large bowl, whisk together oil, sugar, eggs, and vanilla until smooth.
Add flour, cocoa powder, baking soda, baking powder, and salt. Stir until combined.
Fold in shredded zucchini and chocolate chips until evenly distributed.
Pour batter into the prepared pan and smooth the top.
Bake 55–65 minutes or until a toothpick inserted in the center comes out mostly clean.
Cool in the pan for 15 minutes, then transfer to a wire rack to cool completely.