Preheat oven to 350°. Spray a 9 x 5 or 8 x 4 loaf pan with nonstick cooking spray. Set aside.
In a medium bowl, whisk together butter, oil, brown sugar & sugar until dissolved well. Stir in eggs & vanilla and whisk well.
Add zucchini to bowl & stir.
Stir in flour, cocoa powder, baking soda, baking powder, and salt. Fold in a heaping 1/2 cup of chocolate chips.
Pour batter into prepared loaf pan. Sprinkle top with remaining chocolate chips. Bake 45-55 minutes, until a toothpick placed in the center comes out clean. Check after 30 minutes. If it is getting too done on the sides, place foil over the top to allow the center to be fully cooked.
Cool for at least 15-20 minutes. Slice & serve with butter, cream cheese, or hazelnut spread.