Cookies are eaten on their own as a snack or dessert. When crushed, mixed with melted margarine or butter, and pressed into a pan, they make flavorful crusts for pies. Spicy gingersnaps, rich chocolate wafers, classic vanilla wafers, and whole-grain graham crackers, the varieties most frequently used for crusts, are sold in packages in grocery stores.
To make cookie crumbs:
Break the cookies into pieces and grind in a food processor fitted with the metal blade. Or, place whole cookies in a large, heavy-duty plastic bag, press out the air, seal the bag, and crush with rolling pin.