Swiss Meringue Butter Cream frosting

[Laura]

A Martha Stewart recipe (suitable for piping patterns for brain-themed cupcake tops).
Swiss Meringue Butter Cream:
5 large egg whites
1 pound butter (4 sticks) at room temperature divided into tablespoons
1 cup granulated sugar
1 teaspoon vanilla

Bring a sauce pan of water to a simmer and in a metal bowl combine the egg whites and sugar. Whisk the eggs and sugar in the bowl sitting over the pan of water (not in the water) for several minutes until the mixture is creamy and there is no grit if you rub the mixture between your fingers.

Then transfer the eggs to your stand mixer with the whisk attachment and beat them to stiff but not dry peaks. Allow this mixture to cool completely (roughly 10 minutes). Then on medium speed begin slowly beating in all the butter a few tablespoons at a time and then add the vanilla. The mixture might look a little curdled at first, however continue beating until it comes together in a light fluffy mixture. Then remove the whisk attachment and use the paddle to mix the frosting on low speed for 2-3 minutes to beat any air bubbles out of the frosting.