- 1/2 cup (1 stick) unsalted butter at room temperature, or 1/2 cup extra virgin olive oil, plus 1 pat butter or teaspoon olive oil for greasing
- 2 cups all-purpose flour
- 1/2 cup unsweetened Dutch-process cocoa powder
- 1 teaspoon baking soda
- 1/2 teaspoon baking powder
- 1/2 teaspoon fine sea salt
- 1 cup (packed) light brown sugar
- 1 teaspoon pure vanilla extract
- 1 teaspoon instant coffee granules
- 3 large eggs
- 2 cups unpeeled grated zucchini, from about 1 1/2 medium zucchini (keep the remaining 1/2 zucchini for optional garnish)
- 1 cup good-quality bittersweet chocolate chips
- Confectioners' sugar or melted bittersweet chocolate (optional)
- Preheat the oven to 350°F and grease a 10-inch springform pan with butter or oil.
- In a large mixing bowl, whisk together the flour, cocoa powder, baking soda, baking powder, and salt. In a food processor, process the sugar and butter until creamy (you can also do this by hand, armed with a sturdy spatula). Add the vanilla, coffee granules, and eggs, mixing well between each addition.
- Reserve a cup of the flour mixture and add the rest to the egg mixture. Mix until just combined; the batter will be thick.
- Add the zucchini and chocolate chips to the reserved flour mixture and toss to coat. Fold into the batter and blend with a wooden spoon—don't overmix. Pour into the prepared cake pan and level the surface with a spatula.
- Bake for 40 to 50 minutes, until a knife inserted in the center comes out clean.
- Transfer to a rack to cool for 10 minutes, run a knife around the pan to loosen the cake, and unclasp the sides of the pan. Let cool to room temperature before serving.
- Sprinkle with confectioners' sugar, glaze with melted chocolate, or decorate with a few slices of raw zucchini (you don't have to eat them, though).