Beat 3 Tbsp. meringue powder, 1/2 tsp. cream of tartar and 6 Tbsp. warm water in small bowl with electric mixer on high speed until well blended. Gradually add 2 cups icing sugar, beating on low speed after each addition until well blended. Beat on high speed 5 minutes or until stiff peaks form. (To prevent icing from hardening, be sure to keep icing covered at all times.) Use immediately or cover and refrigerate until ready to use.

Place a sheet of plastic wrap directly on surface of icing, then refrigerate until ready to use. Beat with electric mixer on high speed until stiff peaks form just before using.