Look for chocolate cookie crumbs in the grocery store's baking aisle. Or purchase chocolate wafers and process them in a food processor to form coarse crumbs. Wafers may also be crushed in a food storage plastic bag—crush them with a rolling pin.
To make ahead, bake the cheesecake; cool and glaze. Freeze it until the glaze is set. Wrap tightly and freeze it for up to 1 month. Before serving, unwrap and thaw it in the refrigerator for 4 to 6 hours.