Italian Meringue Buttercream

Im going to try this... Im hearing this is the real deal and here is the recipe for whoever needs it



-- 5 egg whites (best at room temp)
-- 1/2 tsp cream of tartar
-- 1/4 cup sugar

-- 3/4 cup sugar
-- 1/4 cup water

-- 1 lb. unsalted butter, softened but not warm or soupy (bringing to room temp and bashing with a rolling pin works well)

-- 1 to 1.5 tsp vanilla extract or liquor for flavoring (** Ruth's note -- RLB suggests using as much as 3 oz. of liquor to flavor, but I find that the emulsion doesn't hold with this much liquid added. 1.5 tsp is even a bit of a stretch.)

-- Equipment: a stand mixer works best, using the whip attachment for the eggs and switching to the paddle when you start adding the butter (to reduce unwanted air bubbles when icing the cake), and you'll need a candy thermometer.