Before I get to the recipe, I going to tap into my nerdy side and briefly describe the process of making Swiss Meringue Buttercream and what separates it from Italian Buttercream recipes.
In a nutshell, perfect Swiss Meringue buttercream is achieved by heating egg whites and sugar over a double boiler. The meringue is then beaten vigorously to get full volume before butter is added to create a smooth and silky buttercream.
Italian buttercream on the other hand, is achieved by whipping the egg whites first and then adding a hot sugar/water mixture to the fully beaten whites. Butter is also added at the end of the process to create Italian buttercream.
Both techniques for buttercream will result in satiny, delicious buttercream. It's really just a matter of preference. As for me - I like Swiss Meringue Buttercream ... OK ... I LOVE Swiss Meringue Buttercream.
10 egg whites
2 1/2 cups sugar
2 teaspoons cream of tartar
1 teaspoon vanilla
3 cups softened butter (6 sticks)
Fill a saucepan with 1 inch of water and place on stove. Place mixing bowl about water and turn heat on low.
Heat mixture, whisking occasionally, until temperature reaches 160. My mixture takes 15-20 minutes to get to temperature but use a thermometer to make sure you don't overheat your mixture. Mixture should be foamy.
Two important tips: Make sure that the butter is softened so that it incorporates evenly and make sure that the meringue mixture is cool enough so that it doesn't melt your butter.
I add 1/2 cup melted chocolate to make decadent chocolate buttercream.
I add 1/4 cup peanut butter to make smooth and creamy peanut butter buttercream.
I fold in a few tablespoons of caramel and a sprinkle of sea salt for a swirled salted caramel buttercream.
I swirl in a few tablespoons of my favorite cookies or candy to create a unique buttercream creation.