Stir together first 3 ingredients in a medium saucepan over medium heat until butter is melted. Cook, stirring constantly, 2 minutes or until slightly thickened; remove from heat. Beat in powdered sugar and 1 tsp. vanilla at medium-high speed with an electric mixer until smooth.
Super easy, tasty frosting. I even saved the extra, heated it up and used it again and it tasted the same as it did fresh. Perfect for brownies, cookies and cake. Dries to a firm texture that transports well.
