Vanilla Buttercream Frosting

The whole eggs, whipped until airy, give this buttercream a light, satiny-smooth texture that melts on the tongue.

1. Combine eggs, sugar, vanilla, and salt in bowl of stand mixer and set bowl over saucepan containing 1 inch of barely simmering water. Whisking gently but constantly, heat mixture until thin and foamy and registers 160 degrees.
2. Fit stand mixer with whisk and whip egg mixture on medium-high speed until light, airy, and cooled to room temperature, about 5 minutes. Reduce speed to medium and add butter, 1 piece at a time. (After adding half of butter, buttercream may look curdled; it will smooth with additional butter.) Once all butter is added, increase speed to high and whip until light, fluffy, and thoroughly combined, about 1 minute. (Frosting can be refrigerated for up to 5 days. Let frosting sit at room temperature until softened, about 2 hours, then, using stand mixer fitted with whisk, whip on medium speed until smooth, 2 to 5 minutes.)

RICH COFFEE BUTTERCREAM FROSTING
Omit vanilla. Substitute 3 tablespoons instant espresso powder in 3 tablespoons warm water and beat dissolved coffee into buttercream after butter has been added.