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 a 9-inch cake.
2 1⁄2 cups (5 sticks) unsalted butter, softened at room temperature
5 cups powdered (10x) sugar
2⁄3 cup cocoa
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 paddle on low speed until smooth, with no lumps, approximately 3 minutes. With the motor running, add the sugar, one cup at atime, only adding the next cup after the first addition is absorbed.
2. Stop the machine and add the cocoa, vanilla, and salt. Paddle on low-medium speed until completely smooth, approximately 2 minutes. Add the water and continue to paddle until light and fluffy, 2 to 3 minutes.
3. The frosting will keep for up to 2 days in an airtight container at room temperature.
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