Ingredients
Equipment
Method
Prep the pan and oven
- Preheat oven to 350°F and grease a 9x5 loaf pan so it’s ready for batter. Set the pan aside for immediate pouring.
Mix dry ingredients
- Whisk all-purpose flour, unsweetened dark cocoa powder, baking soda, salt, and espresso powder together in a bowl until evenly combined. Look for no visible cocoa or baking soda clumps.
Mix wet ingredients
- Beat granulated sugar, eggs, vegetable oil, buttermilk or Greek yogurt, and vanilla extract until smooth. The mixture should look glossy and fully emulsified.
Add zucchini
- Stir in grated zucchini that has been squeezed dry. Fold until the batter looks thick with evenly distributed zucchini strands.
Combine and fold in chocolate
- Fold dry ingredients into wet ingredients until just combined, with no dry pockets remaining. Use gentle strokes to keep the batter fudgy.
Add chips
- Fold in both semi-sweet chocolate chips and dark chocolate chips. Stop when chips are evenly dispersed through the batter.
Bake
- Pour batter into the prepared loaf pan and bake for 55–65 minutes at 350°F. Bake until a toothpick comes out with moist crumbs.
Cool and glaze
- Cool the loaf for 15 minutes before slicing. This rest sets the crumb and helps the glaze stay put.
Make and drizzle glaze
- Melt chocolate glaze ingredients (semi-sweet chocolate chips and cream) together until smooth, then drizzle over the warm loaf. The glaze should look glossy as it sets on the surface.
Notes
For the most fudgy texture, squeeze the grated zucchini very well so the loaf isn’t watery. Store airtight at room temperature for up to 3 days or refrigerate up to 5 days; freeze slices in a sealed bag for up to 2 months. For a dairy-light option, use Greek yogurt plus a splash of water to mimic buttermilk consistency, and keep the glaze creamy with cream or a dairy-free cream substitute.