For the chocolate filling:

1. In a medium saucepan, whisk together the sugar, cornstarch and salt until it is clump-free. Slowly whisk in a little bit of the milk and whisk until completely smooth. Whisk in the rest of the milk.
2. Set the saucepan over low heat and slowly bring to a low simmer, whisking occasionally. Whisk in the chopped chocolate pieces until melted and smooth. Whisk in the butter and vanilla extract. Continue whisking to keep the pudding from getting clumps. Whisk until the pudding has thickened, about 5 minutes. Transfer the pudding to an easy-pour cup/bowl and set aside for assembly. Whisk again before pouring into parfait cups.

For the marshmallow cream filling:

1. In the bowl of an electric mixer, beat together the cream cheese and marshmallow creme on medium speed until light and fluffy. Wipe down the sides of the bowl and mix in the powdered sugar until smooth.

For the graham cracker filling:

1. In a small bowl, mix together the crushed graham crackers with the melted butter until evenly combined.

To assemble the parfaits:

1. Using 7 oz glasses, start to assemble the parfaits by layering together the graham cracker filling, chocolate pudding and marshmallow cream filling. Repeat these layers until the glass is full. Use this process on all the glasses.
2. Top each parfait with a couple of toasted marshmallows if desired. You can serve immediately or refrigerate 1-2 days in advance before serving.