Make the Sugar Free Graham Crackers and allow them to fully cool before using.To make the marshmallow topping, combine the mascarpone cheese and heavy whipping cream in a bowl using a hand mixer until you get a whipped, creamy texture.Add the vanilla extract and liquid stevia and mix with hand mixer one last time.Topping is ready and can be stored in the fridge.Place 1-2 pieces of chocolate onto a graham cracker.