Preheat the oven to 400℉.
In a bowl, beat the eggs, vegetable oil, sour cream, milk, vanilla extract and the sugar together until evenly combined. Separately, mix the flour, cocoa, baking powder and salt together.
Fold in the zucchini and chocolate chips into the batter. Now, fill the muffin cups with the batter. Leave a little room for them to rise at the top.
Place the pan into the oven and bake for 12-15 minutes depending on your oven.
Once they are finished, remove from the oven and allow to cool before serving.