I just made these yesterday for the first time. They were not hard (I used pre-crumbed graham cracker crumbs to cheat just a little more). I also used dark chocolate, because that is what we like around here.
Super yummy. Just like S'mores, but even better. Leave little gaps between the "pancakes" of dough on the top and the marshmallow fluff will puff up and brown a little, like a real toasted marshmallow.