I adapted this recipe from Toba Garrett when I took a cake decorating class from her. She uses the following recipe to practice piping with. Learn: Pastry or Piping Bag – How to Pipe.
FROSTING, ICING, ETC RECIPE HELP
2. INGREDIENTS
1 cup vegetable shortening
1 pound confectioner's sugar, sifted; measure and then, sift
1 tablespoon meringue or egg white powder
3 to 4 tablespoons water
INSTRUCTIONS
1. Fit a stand mixer with a paddle attachment. On low speed, cream shortening with a mixer until softened.
2. Gradually add the sugar, one cup at a time at the side of the bowl with the mixer on low.
3. Add meringue powder and combine. (The icing will appear dry).
4. With the mixer on low speed, slowly drizzle the water into the shortening / sugar mixture. Beat icing for 10 to 12 minutes.
STORAGE
Icing does not need refrigeration. Store in an airtight container for 2 months.
Adapted from The Well-Decorated Cake, by Toba Garrett