This rich, moist chocolate zucchini bread is packed with cocoa and zucchini for a bakery-quality texture that stays tender for days. Nobody will guess there are vegetables inside!
Preheat oven to 350°F (175°C). Grease and dust a 9x5-inch loaf pan with cocoa powder.
In a large bowl, whisk together flour, cocoa, baking soda, salt, and cinnamon.
In another bowl, combine zucchini, sugar, oil, eggs, vanilla, and buttermilk until just blended.
Fold wet ingredients into dry ingredients until just combined. Batter should be thick and slightly lumpy. Fold in chocolate chips or nuts if using.
Pour batter into prepared pan and smooth the top. Bake 55–65 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.
Cool in pan for 10 minutes, then transfer to a wire rack to cool completely before slicing.
Notes
Use medium zucchini (6–8 inches) for best texture. No need to peel or drain – the moisture helps create a tender crumb. Wrap leftovers well and store at room temperature up to 4 days, or freeze slices for 3 months.