Caramel Buttercream Frosting
After frosting the cake, you will have about 1 3/4 cups of buttercream left over. It can be frozen for up to a month.
- 2 1/4 cups sugar, divided
- 1/2 cup water
- 1/2 cup heavy cream
- 9 large egg whites, room temperature
- 6 sticks unsalted butter, softened, divided
- 1 1/2 teaspoons pure vanilla extract
Combine 1 1/4 cups sugar and the water in a medium saucepan. Bring to a boil, stirring to dissolve sugar. Brush down sides of pan with a damp pastry brush, and cook, without stirring, until dark amber. Remove from heat, and gradually stir in cream until completely smooth.
Whisk together remaining sugar and the egg whites in the bowl of a mixer set over a pot of simmering water. Whisk until sugar dissolves and mixture is warm. Transfer bowl to a stand mixer fitted with the whisk attachment, and whisk on medium-high speed until fluffy and cool and stiff peaks form, about 10 minutes. Add butter, 2 tablespoons at a time, whisking well after each addition. Whisk in vanilla. Slowly pour in caramel with mixer on medium speed, and whisk until completely incorporated. Continue to whisk until smooth, about 3 minutes. Use immediately, or transfer to an airtight container and refrigerate up to 3 days. Before using, bring to room temperature, and beat until smooth.