Combine first 3 ingredients in a heavy saucepan. Combine milk and egg; stir well. Add to dry ingredients. Cook over medium heat, stirring constantly, until pudding mixture comes to a boil.
Remove pudding mixture from heat; stir in margarine and vanilla. Pour mixture into 4 (6 oz) custard cups. Cover with plastic wrap, gently pressing directly on pudding. Chill at least 4 minutes. Garnish with snapdragons, if desired.
Yield; 4 (1/2 cup) servings.
