Combine sugar, cornstarch, and salt in a medium saucepan. Gradually blend in the soymilk, stirring until smooth. Cover and cook over low heat, boiling gently for about 5 minutes. Remove from heat and blend in the margarine and vanilla. Pour into dessert cups or a baked pie crust and chill until fully cooled and set.
Butter and Margarine: Butter is a dairy product made from cow’s milk. Margarine typically contains milk or soy, but there are milk-free and soy-free versions available.
Corn Substitutions: Corn is a common ingredient in products. Starch, modified food starch, dextrin and maltodextrin can be from corn. Consult with your physician to find out which corn derivatives you need to avoid. Many corn-free options are available in the US. Find out more about corn substitutions.