Prepare the brownie mix as directed on the box, substituting Cheerwine for the water. Add almond extract and stir. Pour into a 9×9” greased pan and bake as directed. Cool completely, then frost and top with Maraschino cherries, if using.
Beat butter with an electric mixer on medium speed until creamy, about 2 minutes. Sift together powdered sugar, cocoa, and salt in a bowl.
Stir together almond extract and 2 tablespoons of the Cheerwine in a small bowl. Add powdered sugar mixture to butter alternately with Cheerwine mixture, beginning and ending with powdered sugar mixture, beating on low speed until just blended after each addition.
Beat in remaining 1 tablespoon Cheerwine to the mixture, 1 teaspoon at a time, if needed, until desired consistency is reached.