1Heat oven to 350°F. Line bottom and sides of 13x9-inch pan with foil, leaving foil overhanging at 2 opposite sides of pan; spray foil with cooking spray.
2Make brownies as directed on box for fudge-like brownies, using water, oil and eggs. Spread batter in pan.
3Bake 25 minutes or until toothpick inserted 2 inches from edge of pan comes out clean. Cool completely on cooling rack, about 30 minutes.
4In large bowl, beat butter, powdered sugar, 1/4 cup of the whipping cream and the peppermint extract with electric mixer on medium speed until smooth. If frosting is too thick, stir in remaining 1 tablespoon whipping cream. Stir in food color. Frost brownies. Refrigerate at least 2 hours. Use foil to lift out of pan. Cut into 8 rows by 6 rows. Top with shaved candies.