Dry ingredients (cocoa powders, baking powder, flour, salt).
In a separate bowl butter and sugars together until combined.
Add eggs and vanilla to butter and sugar mixture.
Dry ingredients (cocoa, baking powder, flour, salt) with the wet ingredients (butter, sugar, eggs vanilla).
Roll dough out between two pieces of parchment paper until it is 1/8th inch thick.
Cut into rectangles, approximately 5 inches long.
Freeze rectangles in the freezer to set and harden.
Remove rectangles from freezer, arrange on a baking sheet about 1 inch apart and pierce with a fork.
Bake at 350 degrees for 6-9 minutes until edges are set.
Freeze again for 30 minutes to harden and set (can be done in a stack if parchment paper is between them).
Spread ice cream on one cookie, and sandwich another on top of it.
Freeze for one hour to set.
Store in zip lock bag for up to 3 months.