1Heat oven to 350°F (325°F for dark or nonstick pan). Grease bottom only of 13x9-inch pan with shortening or cooking spray.
2Make brownies as directed on box. Cool completely, about 1 1/2 hours.
3Frost brownie with frosting. Sprinkle with candy sprinkles. For brownies, cut with plastic knife into 6 rows by 4 rows. Store covered at room temperature.