Place Cadbury Mini Eggs in a ziploc bag and smash with a rolling pin by rolling over the eggs and pressing hard. Leave some of the eggs out if you want some whole eggs on the cookies, as pictured.
Cream together butter and both sugars; add eggs one at a time, mixing well. Add vanilla and mix again.
In a separate bowl, whisk together flour, cocoa, salt, baking powder, and baking soda. Slowly add dry mixture to the wet mixture to incorporate. Then add the crushed up candy eggs with a wooden spoon.
Drop cookies by the spoonful or with a cookie scoop onto a greased cookie sheet. Bake 7-9 minutes at 350°.