1/3 cup butter
2 tablespoons hazelnut liqueur, such as Frangelico
3 cups sifted confectioners' sugar
2 to 3 tablespoons half-and-half
Cream butter with an electric mixer at medium speed. Add Frangelico. Gradually add confectioners’ sugar, alternating with half-and-half, beginning and ending with powdered sugar. Beat until mixture reaches spreading consistency.