Love this Retro Thanksgiving Campfire Marshmallow Ad from the 1920s. You'll definitely want to try the Campfire Apple Mallows. So easy and fun.. And, of course Sweet Potatoes with Marshmallow topping is a perfect Thanksgiving side dish. But here's a recipe you may not have seen before: Marshmallow Fudge Cake. This cake is easy to make for Thanksgiving or just about any time.