Cooked Buttercream Frosting - cooking recipe

Ingredients

4 to 5 Tbsp. water, divided
1 lb. box confectioners sugar, divided
1/4 c. butter or margarine, softened
1 tsp. vanilla
1 egg yolk

Preparation

Microwave:
In small bowl, stir together 1 tablespoon of water, 3 tablespoons of the sugar and the yolk.
Cook, stirring every 15 seconds, until bubbles, about 45 seconds to 1 minute. Set aside.
Allow to cool about 15 minutes.