Preheat oven to 350º. Grease and flour a Bundt pan.
In a medium bowl, whisk together flour, cocoa, baking powder, baking soda, and salt. Set aside.
In a large bowl, cream butter and sugars with mixer until fluffy.
Add eggs, vanilla and milk to the butter mixture and mix until combined.
Stir in dry ingredients and mix until well blended.
Fold in zucchini and chocolate chips.
Pour into prepared pan. Bake until until a toothpick inserted into center of cake comes out clean, 50-60 minutes.
Allow to cool in pan for 10-15 minutes before inverting onto a wire rack to cool completely.