Vanilla Buttercream

This is from All You Magazine, it goes along with the Carrot Cupcake Recipe I posted (Carrot Cupcakes).

• Ready In: 20 mins
• Yields: 3 cups

Ingredients

• 4  egg whites
• 1  cup granulated sugar
• 1 1⁄4 cups  cold unsalted butter (2 1/2 sticks,cut into cubes)
• 1⁄4 teaspoon salt
• 1 1⁄2 teaspoons vanilla extract

Directions

1. Set electric mixer bowl over a saucepan of simmering water.
2. Whisk egg whites and sugar until sugar is nearly dissolved.
3. Remove bowl from pan.
4. Whip mixture at high speed until stiff.
5. Reduce speed and beat until cool, 5 minutes. (mixture must be cool before adding butter).
6. Add cold butter 1 piece at a time at medium low speed.
7. After all butter is added, beat at high speed until fluffy.
8. Add salt and vanilla and mix at low speed until well blended.
9. Time to frost the cupcakes!