1 (20 oz.) pkg. Oreo cookies, crushed
1 tbsp. butter, softened
1/2 gal. vanilla ice cream, softened
16 oz. chocolate syrup
16 oz. whipped topping

Reserve 1 cup cookie crumbs. Combine remaining crumbs with butter. Pat into dish. Spread ice cream over cookie mixture. Freeze until firm. Pour chocolate syrup over ice cream. Freeze until firm. Spread whipped topping over syrup. Sprinkle with remaining crumbs. Cover with foil. Store in freezer.