PREHEAT oven, grease 13 x 9-inch baking pan and prepare brownie mix batter according to package directions.
SPREAD batter into prepared baking pan. Sprinkle with 1 cup morsels.
BAKE according to package bake times for 13 x 9-inch pan size. Cool completely in pan on wire rack.
SPREAD frosting over brownie. Sprinkle with remaining morsels. Cut into bars. Store covered in cool place.
VARIATION: Along with sprinkling the morsels, top with 1/4 cup coarsely crushed peppermint candies, cinnamon candies or 2 tablespoons Valentine sprinkles.