Put the cream cheese in a large mixing bowl and beat with electric mixer until smooth.
Add in the powdered sugar and continue to mix until incorporated.
Mix in the Cool Whip and vanilla; beat until no lumps appear.
Fold in the miniature marshmallows and chopped chocolate chips.
Line a 9x9 pan with aluminum foil leaving an overhang on opposite sides to lift the bars out.
Layer about 7 to 8 graham crackers to the bottom of the pan, breaking them as needed to fit.
Pour the cheesecake mixture over the graham crackers, and smooth it out with a spatula.
Layer the rest of the graham crackers on top.
Chill in the freezer for 4 hours, or over night.
Spread the marshmallow fluff on top, smooth it out with a spatula.
Toast it with a kitchen torch, optional, or garnish with chopped chocolate chips.
Cut and serve.
Refrigerate any leftovers.