Italian Meringue Buttercream is the King of all buttercream. Silky, light, and a dream to pipe! This is the best out there!
In a saucepan, boil water and sugar on medium. Bring to 240 degrees.
At the same time the water and sugar are boiling, begin whisking your egg whites and pinch of cream of tarter.
Then slowly drizzle the syrup in a steady stream into the egg whites (beating on highest speed). Do not pour directly onto whisk attachment.
Let mixer whip for about 10-12 minutes.
Then add in butter by the tablespoon.
Beat another 5 minutes,
Then add in vanilla extract.
At the very end sprinkle on salt.
You can use this recipe as a base for any flavor of Italian Meringue Buttercream. This easily doubles to frost a larger cake.