For a creamier frosting, use milk instead of water, but note that you must refrigerate it, as well as any cakes filled or iced with it. Let it come to room temperature before using, and whip briefly by hand to refresh it. Makes about 4 cups, enough to fill and ice one 9-inch cake.
2 1⁄2 cups (5 sticks) unsalted butter, softened at room temperature
5 cups powdered (10x) sugar
1 tablespoon pure vanilla extract
1⁄4 teaspoon fine sea salt
3 tablespoons lukewarm water
1. Put the butter in the bowl of a stand mixer fitted with the paddle attachment and mix on low speed until butter is smooth with no lumps. With the motor running, add the sugar, 1 cup at a time, only adding the next cup after the first addition has been integrated into the mixture.
2. Stop the machine and add the vanilla and salt. Paddle on low-medium speed until completely smooth, approximately 2 minutes. Add the water and continue to mix until light and fluffy, 2 to 3 minutes.
3. The frosting can be kept in an airtight container at room temperature for up to 2 days.
CAKE BOSS: STORIES AND RECIPES FROM MIA FAMIGLIA, BY BUDDY VALASTRO, COPYRIGHT © 2010 BY DISCOVERY LICENSING, INC., PUBLISHED AT $25.99 BY FREE PRESS, A DIVISION OF SIMON & SCHUSTER, INC., 1230 AVE. OF THE AMERICAS, NEW YORK, NEW YORK 10020