Prepare cake mix as directed. Pour into cupcake liners and bake as directed.
Let cupcakes cool before decorating.
In a standing mixer fitted with a whisk, mix together sugar and butter. Mix on low speed until well blended and then increase speed to medium and beat for another 3 minutes.
Add vanilla and cream and continue to beat on medium speed for 1 minute more.
Frost cooled cupcakes. After you have frosted the cupcakes, sprinkle the top with red sprinkles for the hat. Then place 3 marshmallows under the sprinkles to finish off the hat. Place 5-6 marshmallows at the bottom of the cupcake for the beard, then add 3 marshmallows on top of beard. Use frosting for the 'glue' to hold the marshmallows in place.