Mix the margarine (or butter), vanilla and water with a fork in a bowl.
Blend in the Splenda® Icing Sugar Mix.
Use as desired.
Notes
To make chocolate icing, blend 1 teaspoon of unsweetened cocoa powder in which the margarine, vanilla and water.You may wish to try other extract flavours such as lemon, butterscotch, almond, etc., and perhaps also some colouring.You may need / wish to add up to another teaspoon of water (or milk), depending on how thin you want it, etc.There's not really any advantage to using electric beaters with this: a simple fork gets the same results.