Quick Sugar Cookie Icing

• 4 cups confectioners' sugar
• 1/2 cup margarine
• 5 tablespoons milk
• 1 teaspoon vanilla extract (Peppermint Extract is tasty too!)
  
• food coloring

In a large bowl, cream together the confectioners' sugar and shortening until smooth. Gradually mix in the milk and vanilla with an electric mixer until smooth and stiff, about 5 minutes. Color with food coloring if desired. Use of a piping bag is recommended but not required.