- 2 c. granulated sugar
- 1 c. egg whites (about 8 egg whites)
- 1 lb (4 sticks) unsalted butter, room temperature
- 1 c. creamy peanut butter
- Pinch of kosher salt
- 1 to 2 tsp. vanilla extract
- In a heat-proof electric mixer bowl combine sugar and egg whites. Place the bowl over a pot of simmering water and heat, whisking frequently, until the sugar is completely dissolved and the mixture is hot to the touch, 160˚F.
- Remove the bowl from the stove and attach it to the base of your mixer. Beat the mixture with the whisk attachment on high until you get a stiff-peaked meringue and the meringue has cooled to room temperature or as close to room temperature as possible.
- While the meringue is mixing, cut the butter into eight pieces per stick (I cut the pieces into tablespoon increments) and let it come to room temperature while the meringue whips. (Alternatively, you can precut your butter and bring it to room temperature and then let it chill for a bit while you start to make this frosting. But once you start whipping the meringue, you should bring it out to bring it to room temperature.) However, don’t worry if your butter is a little bit cold yet and not completely room temperature. I still managed to get the desire consistency and my butter was not quite room temperature and actually a bit stiff.
- Add the butter, one piece at a time, to the meringue, while beating on high speed. If the meringue falls or starts to look curdled or liquidy, keep adding the butter and beating. The frosting should come together into a thick frosting. (This happened to me the first time I made a Swiss Meringue Buttercream.)
- Add salt, peanut butter and vanilla. If the frosting gets a bit runny when you add the peanut butter try beating it on high for a bit or you can firm it up in the fridge. Frost immediately, or chill it to firm up. (I chilled it slightly before frosting.)
The thing about Swiss Meringue Buttercream frosting is that the more you make them, the easier they get. The first two times I made this type of frosting it seemed to take forever. When I made it this last time it seemed to come together in a snap.
The recipe I based this recipe upon called for 1 1/2 pounds of butter. I found that one pound was enough. However, the consistency of my frosting seemed a bit on the soft side when all was said and done, so in retrospect I wonder if I should have used the full pound and half of butter.
This frosting is perfect for the outside of any cake or with a light and airy cake. I found it didn’t hold as well as I would have liked with the dense thick layer cake I made. But I would definitely make this frosting again. And again. And again!
Recipe rating: 1/2