Preheat your oven to 350°F (175°C). Grease a loaf pan.
In a mixing bowl, combine grated zucchini, sugar, oil, and vanilla extract.
In another bowl, whisk together flour, cocoa powder, baking soda, and salt.
Gradually add the dry ingredients to the wet mixture, stirring until just combined.
Pour the batter into the prepared loaf pan.
Bake for 60 minutes or until a toothpick inserted into the center comes out clean.
Let it cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.