Add egg whites to the bowl of a stand mixer and beat on low speed until frothy (suggestion: reserve egg yolks for use in another recipe such as homemade egg noodles)
Turn mixer speed to medium-high, and best until soft peaks form.
While eggs are beating, add one cup of sugar and 1/4 cup water to a small sauce pan. Heat over medium heat to 240°.
After egg white wave formed soft peaks, add remaining 1/4 cup of sugar and best until stiff peaks form. Now, here comes the tricky part, but honestly it’s not as hard as it sounds.
While egg whites are beating, slowly pour sugar syrup into them in a thin stream. You can pour the syrup into a spouted pitcher if that makes you more comfortable, but you may find it just as easy to pour directly from the sauce pan as long as lift from the shoulder, rather than trying to tip the pan from your wrist… If that makes sense.
Continue beating for a few minutes to cook the eggs through.
Start adding the butter a tablespoon or so at a time, beating all the while.
Make sure the butter is unsalted! I made this one time with salted butter and -wow! There’s not enough sugar in this recipe to cover up that salt.Moving on…
After you add the butter, it’s all going to break down and you’ll think you’ve ruined the icing, but just keep beating! It may take several minutes, But the icing will come together.
If the mixture is very warm… It can take up to ten minutes or longer for the icing to “make”.
If the mixture is too cool… You may have to crank the mixer up and beat the tar out of the icing to make it smooth. In this case, it’s been my experience that the icing tends to lose some of its volume and be a little more greasy, so I actually prefer warm to cool.
That’s all there is to it!
Important note: your instruments need to be completely grease free for the egg whites to whip properly! If you have any doubt about your mixing bowl/beaters, wash them with hot water and rinse with vinegar water.