Preheat oven to 350.
Combine flour, cocoa, baking powder, baking soda, and salt in a large bowl.
In another large bowl, beat the butter and sugar together until it is light and fluffy. Mix in the eggs and vanilla. Slowly mix in the milk.
Sift dry ingredients into the creamed mixture.
Using a small cookie scoop or rounded spoon, drop the batter by the teaspoon worth on parchment paper lined cookie sheets, about 2 inches apart. Bake for 10-13 minutes, or until they spring back when you touch them.
Cool on baking sheets for 5 minutes. Then remove to cooling racks to finish cooling.