Two-Ingredient Peanut Butter Fudge

Line an 8x8-inch baking pan with foil, allowing foil to extend over edges of pan. Coat foil with nonstick cooking spray. In a medium microwave-safe bowl place peanut butter and frosting. Microwave on 100% power (high) for 45 to 60 seconds or until softened, stirring once. Stir until smooth. Spoon into prepared pan. Cover and chill at least 30 minutes or up to 24 hours. Use foil to lift uncut fudge from pan. Cut into 1-inch pieces. To store, place in an airtight container. Chill up to 2 weeks or freeze up to 2 months.