over a double boiler, in a large metal bowl,
Whisk together the granulated sugar and the egg whites until the
mixture reaches approx, 115 degrees and sugar granules have dissolved
and are no longer gritty to the touch
pour this mixture into the metal bowl of a kitchen aid mixer with the whisk
attachment. Whip on high speed until it is thick and glossy and white in color, very firm
sift powder sugar, add all at one time to meringue on low speed until all mixed in.
make sure butter and shortening are at room temp, add in 2-3 fast additions 1-2-3-FAST
turn the speed up to high and let it mix until smooth, add vanilla ext.