When i was living in China (20 years ago) for about 10 cents US you could get a sweet potato from out of the embers in a barrel from any of the street food stalls and it was roasted to perfection, nothing else needed. Here in New Zealand we call it kumara and I prefer it with butter, salt and pepper. Added Marshmallows does seem like something that would happen to the sweet little potatoes who find themselves in America but you won't convince me to give it a try!