This is a basic "buttercream" frosting. You can add a little more vanilla extract to make it a little extra special tasting.
1/3 cup palm shortening or Earth Balance margarine
3 cups powdered sugar
2 tbsp. rice milk plus more for thinning
2 tsp. vanilla extract
Beat palm shortening at high speed with an electric mixer until fluffy. Add 1 cup of powdered sugar and beat. Add a tablespoon or so of rice milk and the vanilla extract and beat utnil well blended. Beat in the remaining sugar 1/2 cup at a time until all the sugar has been used, thinning with rice milk as necessary until a nice thick frosting consistency is reached.
*For chocolate buttercream frosting, sift 1/3 cup cocoa powder into the powdered sugar before beating it into the shortening.