I'm curious as to how I would exchange powdered egg whites (as mentioned in the recipe) for the egg whites. Would I add water to the powder or what? I've done it with egg whites and no problems, but just in case, I'd like to try this also. Any thoughts?

http://www.cakecentral.com/cake_recipe-2015-8-Italian-Buttercream-Meringue-Frosting.html

Usually, the package will tell you how much liquid to add to how much powder to equal one large egg white.

I found it helpful to sift the dry eggwhite powder to avoid tiny lumps.

Oh, ok. Thanks!