Place the marshmallow sticky-side down on half of a graham cracker.
Cook:
Line up the graham crackers topped with the marshmallow inside the preheated air fryer. Cook for 2 minutes at 390F. If you like yours burnt, add 30 more seconds.
Assemble:
Remove the gooey marshmallow half from the air fryer. Top the marshmallow with the milk chocolate and use another graham cracker half to close the sandwich.