Royal Icing (for Easy Holiday Sugar Cookies)

From Cooks Illustrated, for their Easy Holiday Sugar Cookies.

INGREDIENTS

2-2/3 cup (10-2/3 oz) confectioners sugar

2 large egg whites

1/2 tsp vanilla

1/8 tsp salt

PREPARATION

1. Using standing mixer with whisk attachment, whip all ingredients about 1 minute on medium low until combined.

2. Increase speed to medium high, whipping until soft glossy peaks form, about 3-4 mins. Scrape sides of bowl as needed.

3. After cookies are iced, let icing dry completely before serving or packing.