4 cups of powdered sugar
1/2 cup of soften butter or marg.
1/2 cup shorting
1 tablespoon vanilla
2 or 3 tablespoons of milk
In a large bowl put sugar, butter & shorting, with a large spoon mix well until you dont see any sugar much add vanilla mix on low speed add 2 to 3 tablespoons of milk mix well.
This should frost 2 9x13 cakes, This is the best icing i have ever had.