1Heat oven to 350°F. Grease 13x9-inch pan with shortening or cooking spray.
2Make and bake brownies as directed on brownie mix box. Cool completely, about 1 hour.
3In medium bowl, stir together frosting, marshmallow crème, mint extract and food color until well blended. Spread over cooled brownies. Sprinkle with cookies; press in slightly. For bars, cut into 6 rows by 4 rows.