Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan or line it with parchment paper.
In a large bowl, whisk together flour, cocoa powder, baking soda, baking powder, salt, and cinnamon.
In another bowl, beat eggs, oil, granulated sugar, brown sugar, and vanilla until smooth.
Stir the wet ingredients into the dry ingredients until just combined.
Fold in the shredded zucchini and chocolate chips—don’t overmix!
Pour the batter into your prepared loaf pan. Sprinkle a few extra chocolate chips on top for good measure.
Bake for 45–50 minutes, or until a toothpick inserted into the center comes out mostly clean (a few crumbs are fine).
Let cool in the pan for 10 minutes, then transfer to a wire rack to cool completely. Slice and enjoy!