Add a small amount of hot mixture to egg yolks; return all to the pan, stirring constantly. Cook 2 minutes longer or until mixture thickens, stirring constantly. Remove from the heat; stir in vanilla. Cool to room temperature.

In a mixing bowl with the whisk attachment, cream butter until fluffy, about 5 minutes. Gradually beat in cooked sugar mixture. Beat in confectioners' sugar until fluffy, about 5 minutes.

If necessary, refrigerate until frosting reaches spreading consistency.

Store in the refrigerator.

Submitted by: Roof Raiser 101