Source: Martha Stewart Weddings, Fall
- 2 cups (4 sticks) unsalted butter
- 4 2/3 cups confectioners' sugar
- 2/3 cup chilled freshly brewed espresso
Melt butter in a medium saucepan over medium heat. Let cool 10 minutes. Pour through a fine sieve into a clean pan.
Return to heat. Add sugar; whisk until sugar has dissolved. Bring to a simmer; cook 1 minute. Whisk in espresso.
Pour through a fine sieve into a medium bowl; let cool until slightly thickened, 5 to 7 minutes. Whisk before using.