Prepare brownies according to package directions, baking them in a 9″x13″ inch pan. Let them cool. Frost entire tops of brownies with chocolate frosting. Cut brownies, on a diagonal, 2 inches apart. Then turn pan a quarter turn and cut again. Remove football shaped brownies from pan to a serving platter. You can use the smaller pieces to snack on before your football party. Place white frosting in a ziplock bag. Cut a small hole in the corner. Pipe laces on each brownie.