Easy go to recipe . If you wish, use half shortening and half unsalted butter.
Ingredients
2 cups confectioners' sugar
1/2 cup shortening
1 tablespoons water
1/2 teaspoon clear imitation vanilla extract
Directions
In a large bowl, combine sugar, shortening, water and vanilla. Beat on low speed to combine, then beat on medium speed for a full five minutes. It won't look like Icing at first, but keep the mixer going for a full five minutes, and then you're done!
Add 2 tablespoons of corn syrup if you want the icing to harden so you can stack cookies.