Combine butter and half of the cookie crumbs; press into a greased 13-in. X9-in. X2-in. Pan. Carefully spread vanilla ice cream over crust. Combine half of the crushed candy bars and remaining cookie crumbs; sprinkle over vanilla ice cream. Carefully spread the chocolate ice cream over top. Sprinkle with the remaining crushed candy bars. Cover and freeze until firm, 6 hours or overnight. Yield: 12-16 servings.