Caramel Buttercream Frosting

1 cup plus 2 TBS sugar
1/4 cup water
1/4 cup heavy cream
12 ounces or 3 sticks unsalted butter, softened
4 large egg whites, room temperature
1 tsp pure vanilla extract

Bring t1/2 cup plus 2 TBS sugar and the water to a boil in a medium saucepan. Wash sides of pan with a wet pastry brush to prevent sugar crystals from forming. Cook undisturbed, until caramel is dark amber in color. Remove from heat, and slowly add cream, stirring with a wooden spoon until smooth, let it cool before using.