Also known as heritage frosting, boiled milk frosting or flour buttercream, Ermine Buttercream frosting is the best of both worlds. This buttercream is an old-fashioned staple icing that is time-tested, but uncommon enough to make an impression! Originally used to ice and decorate red velvet cake, this unique twist on buttercream is light, not overly sweet and egg-free. It’s simpler than you think to make and pipes beautifully.
In medium saucepan, stir together sugar, flour and salt. Whisk in milk until smooth. Cook over medium heat, stirring constantly, until very thick, about 5-7 minutes. Remove from heat and pour into medium bowl; press plastic wrap over top of mixture and sides of bowl to seal completely and prevent a skin from forming. Let cool to room temperature, about 1 to 1-1/2 hours.
In medium bowl, beat butter with electric mixer at medium speed for 5 minutes until light and fluffy. Add milk mixture, 1 tablespoon at a time, to whipped butter and beat until smooth, scraping down bottom and sides of bowl often. Add vanilla and beat 3 more minutes, or until frosting reaches the consistency of whipped cream.