Place sprinkles on a large plate. Rub the rim of a tall milkshake glass with marshmallow fluff . Dip the glass in sprinkles and set aside.
For the milkshake, using a blender, combine vanilla ice cream, red velvet cake mix, milk, cream cheese and vanilla extract. Blend until smooth and pour into prepared milkshake glass. Spoon marshmallow fluff over top of the milkshake to garnish.