Meringue Butter Cream
- 3 cups granulated sugar
- 12 large egg whites
- 2 pounds (8 sticks) unsalted butter, softened and cut into tablespoon-size pieces
- 2 teaspoons pure vanilla extract
Whisk sugar and egg whites in a large heatproof bowl set over a pan of simmering water until sugar is dissolved and mixture registers 140 degrees.on an instant-read thermometer, 2 to 3 minutes.
Fit an electric mixer with the whisk attachment, and beat the egg-white mixture on high speed until it holds stiff (but not dry) peaks and mixture is fluffy and cooled, about 10 minutes.
Reduce speed to medium-low, and add butter several tablespoons at a time, beating well after each addition (meringue will deflate slightly as butter is added). Add vanilla; beat until frosting comes together, 3 to 5 minutes. Beat on lowest speed until air bubbles diminish, about 2 minutes. Stir with a rubber spatula until frosting is smooth.