In a large saucepan, combine the sugar substitute, cocoa, cornstarch
and salt. Stir in milk until smooth. Cook and stir over medium-high
heat until thickened and bubbly. Reduce heat; cook and stir 2 minutes
Remove from the heat. Stir a small amount of hot filling into egg
yolks; return all to the pan, stirring constantly. Bring to a gentle
boil; cook and stir for 2 minutes. Remove from the heat.
Gently stir in vanilla extract.
Cool for 15 minutes, stirring occasionally.
Transfer to individual dessert dishes.
Cover and refrigerate for 1 hour.
Just before serving, top with marshmallows and walnuts.
Yield: 5 servings.
This recipe was tested with Splenda No Calorie Sweetener.