Preheat oven to 350F and line 10 muffin tin cups with muffin liners.
Grate zucchini on a cheese grater. Use a tea towel to squeeze out the excess moisture from the zucchini. Really squeeze it! Pour grated zucchini into a large mixing bowl with the egg, sugar, vegetable oil and vanilla extract.
In a separate bowl combine the flour, cocoa powder, baking soda and salt. Fold dry ingredients into wet with a rubber spatula. The batter will be thicker than a standard muffin batter.
Mix in the chocolate chips and place ¼ cup of batter in each of 10 muffin cups. Top with more chocolate chips.
Bake at 350F for 22-24 minutes. Cool completely and enjoy.
