Sift together the flour, cocoa and baking powder. Set aside.

Cream the butter, vanilla extract and sugars well, before adding the eggs one at a time and beating until light and fluffy. Fold in the dry ingredients and when they are almost mixed in fold in the chocolate chips. Try not to over mix the dough which will be quite stiff.

Roll the dough in 1 inch balls and place them 2 inches apart on a parchment paper lined cookie sheet. Press the dough balls down slightly with the bottom of a drinking glass. Bake at 350 degrees F for 10-12 minutes, being careful not to over bake them. Cool on the sheet for a few minutes before transferring the cookies to a wire rack and letting them cool completely. Sandwich two cookies together with some peanut butter frosting.

Beat together well until smooth. Use only enough milk to bring the frosting to a spreadable texture. It is best for these cookies to have the frosting as stiff as possible.