This old-time buttercream has been used through many generations, and is the perfect finish to almost any cake or cupcake recipe. The classic flavor is vanilla; however, you can substitute other flavors such as almond or mint in place of the vanilla for a delicious variation. Many recipes for American Buttercream are so overly sweet they are unpleasant to eat. But this American Buttercream recipe has the perfect balance of butter and sugar, making it not too sweet. A pinch of salt plus a splash of whipping cream and vanilla is all it takes to finish making this luscious and creamy frosting.