Graham pie crusts are just ground graham crackers, a little sugar and margarine added and pressed in a plate. If you look up a homemade graham crust you could use it and just substitute chocolate plain cookies and grind them into crumbs. You put your cookies between wax paper and roll over them with your rolling pin until you get crumbs. Look for a key lime pie or grasshopper pie recipe because they are sometimes made with chocolate crumb crusts.