The two keys to making this a smooth dip are to start with room temperature cream cheese and to beat the cream cheese in the mixer alone to start.
Place the room temperature cream cheese alone in the bowl of a stand mixer fitted with the whisk or paddle attachment. Beat it on high speed until smooth and creamy.
8 ounces cream cheese
Add the marshmallow creme and continue beating until the dip is silky smooth.
7 ounces Jet-Puffed marshmallow creme
Transfer the dip to an airtight container and refrigerate until serving.