This recipe is very similar in both ingredients and preparation to Flour Buttercream, but even easier to make. Ermine Buttercream has a delicious vanilla flavor that is not too sweet, with a light and creamy texture, and is the perfect accompaniment to any flavor of cake. Ermine Buttercream goes by many names, such as Flour Buttercream, Boiled Milk Frosting, Cooked Flour Frosting, Roux Frosting, Cloudburst Frosting, Heritage Frosting and Mock Buttercream. This frosting is perfectly spreadable and also pipes beautifully using a pastry bag and decorating tips. Original Ermine Buttercream was made by cooking flour and milk into a thick paste, creaming together sticks of butter and granulated sugar, adding the cooked paste, and continuing to beat until fluffy. If not done carefully though the finished frosting may have small lumps of flour throughout. This recipe has three major changes from the original to produce a more perfect frosting. First some of the flour is substituted with cornstarch to make the frosting a bit thicker and more easily spread on a cake. Second cooking the sugar along with the milk, flour, and cornstarch seems to make the cooked paste smoother with no lumps. Use whole milk if possible for the tastiest frosting. Last is adding the butter. It’s important to make sure the cooked paste is cooled to room temperature. The butter is added in small amounts at a time to make sure that each addition of butter is completely emulsified with the cooked paste. Then the whole buttercream mixture is whipped, whipped, whipped until it is a light and fluffy.