Swiss Meringue Buttercream

1. 1

   Heat sugar and eggs Bring a saucepan filled with about 2 inches of water to a simmer.

2. 2

   Meanwhile, combine sugar, egg whites, and salt in a large heatproof mixing bowl.

3. 3

   Set bowl over (not in) simmering water, and whisk until whites are warm to the touch and sugar is dissolved, 2 to 3 minutes.

4. 4

   (Heating the eggs relaxes their proteins, enabling the eggs to whip up higher and more quickly; the sugar also melts, for a silky smooth consistency.)

5. 5

   Test by rubbing between your fingers; the mixture should feel smooth.

6. 6

   Whip meringue Attach bowl to a standing electric mixer fitted with the whisk attachment, and beat on low speed until foamy.

7. 7

   Add cream of tartar, and beat on medium-high speed until stiff, glossy peaks form and mixture is cooled completely, about 10 minutes.

8. 8

   Mix in butter Reduce speed to medium-low; add butter 2 tablespoons at a time, beating to incorporate fully after each addition.

9. 9

   Dont worry if the buttercream appears curdled at this point; it will become perfectly smooth again with continued beating.

10. 10

    After all the butter has been incorporated, beat in vanilla.

11. 11

    Finish Switch to the paddle attachment.

12. 12

    Beat on the lowest speed to reduce air bubbles, 3 to 5 minutes.

13. 13

    Let stand, covered with plastic wrap, at room temperature.

14. 14

    (If not using the same day, transfer to airtight containers and store in the refrigerator up to 3 days or the freezer up to 1 month.

15. 15

    Before using, bring to room temperature; beat with the paddle attachment on the lowest speed until smooth and pliable, about 10 minutes.)

16. 16

    Follow recipe above, adding 5 1/2 ounces melted and completely cooled semisweet chocolate along with the vanilla.

* Per serving · 4 servings · Values may vary.