used to frost red velvet cake. French buttercream French buttercream (also known as pâte à bombe-based buttercream or common buttercream) is made with whipped egg yolks. German buttercream Custard-based buttercream, also known as German buttercream or crème mousseline, is prepared by beating together pastry cream and softened butter, and may be additionally sweetened with extra confectioners' sugar. See also List of butter dishes References Foods featuring butter Cake decorating