Perhaps it was a situation where it is very cold like in some of the deserts on the northern-most or southern-most regions of the world. Otherwise, the ice cream would melt, thus making it more of an ice cream sea than a desert. And of course, this is provided that this were in a world perhaps less like our own and more, say, like Kirby. In either case it is completely possible that he MEANT ice cream desert. Perplexing indeed.