Combine cookie crumbs and 1 cup ice cream in a bowl; stir well. Spread into bottom of a 13- x 9-inch baking dish. Freeze until firm. Spread remaining ice cream over cookie mixture; cover. Freeze until firm.
Remove lid from hot fudge topping; microwave, in jar, at HIGH 45 seconds. Drizzle topping over ice cream; cover. Freeze 4 hours or until firm. Cut into 24 squares.