In a saucepan, on medium heat, combine sugar and cornstarch. Gradually whisk in milk.
Bring just to a boil, then reduce heat and simmer for 2 minutes or until thickened, whisking constantly to avoid burning.
Remove from heat, and whisk in marshmallow crème until smooth.
Cool slightly, about 5 minutes.
To assemble parfaits, place about ¼ cup pudding in each of 4 parfait glasses. Sprinkle on chocolate chips, then a layer of crumbled graham crackers. Repeat each layer again, two more times. Place in refrigerator and let chill for about 30 minutes to set.
When ready to serve, garnish with whipped cream and sprinkles then enjoy!