Combine first 5 ingredients in a food processor or blender; process until smooth. Place tofu mixture in a large bowl. Fold in whipped topping. Pour mixture into the freezer can of an ice-cream freezer; freeze according to the manufacturer's instructions. Stir in crushed cookies during last 5 minutes of freezing. Spoon ice cream into a freezer-safe container; cover and freeze 1 hour or until firm. Garnish with a whole cookie, if desired.