No-Cook Fluffy Frosting

⅓ C soft margarine
1 t vanilla
¼ t salt
2 unbeaten egg whites
1 lb box powdered sugar
1 T milk

∙ Cream butter with vanilla and salt till fluffy.
∙ Add egg whites and sugar alternately, a little at a time, beating well after each addition.
∙ Add milk and beat.
∙ If necessary, add more milk to make desired spreading consistency.
∙ Makes enough for a 9x13 cake.