1Place 1 C. of champagne in small saucepan, simmer over med. high heat until reduced to 2 T. Transfer to a small bowl or condiment cup and allow to cool. In the bowl, cream softened butter and powdered sugar together. Once the frosting is thick and fluffy. pour in the reduced 2 T. champagne plus 1 T. champagne from the bottle and mix well. Frost.