Shred the zucchini.
Pat dry the shredded zucchini but don’t squeeze the water out.
In a large bowl, whisk the flour, baking powder, baking soda, salt, cinnamon, nutmeg, and chocolate chips together until well combined and set aside.
In a medium bowl, whisk the cooking oil, brown sugar, granulated sugar, egg, and vanilla until well combined.
Stir in the shredded zucchini. Pour the wet ingredients into the dry ingredients and whisk until just combined. Be careful not to overmix.
Pour the batter into the prepared loaf pan.
Optional: sprinkle extra chocolate chips on top of the batter.
Bake 45 - 50 minutes. The bread is done when a toothpick inserted in the center comes out mostly clean with no raw batter.
Place the loaf pan on a wire rack and cool 5 minutes in the pan.
Run a knife around the edge and remove the bread from the pan. Place the bread on the wire rack to cool completely, about 1 hour.