I use 6 Tbsps of meringue powder (CK brand) for 2 lb of powdered sugar. I don't sift the sugar, but I do dissolve the meringue powder in water first (2/3 cup for 2 lb sugar). I whisk it in the measuring cup, let it sit for at least a half an hour, then strain it before adding it to powdered sugar along with flavoring and 1 tbsp corn syrup.