for some reason i was thinking that dairy queen was like mcdonalds. but, they haven't even spread across the entire united states. go to Oddono's Ice Cream, Marylebone, London. yahoo says they have ice cream cakes, however it maybe a cream cake with a mistaken identity, most of the searches have led to this.
the thing that i miss in the midwest america is gelato and sorbets. but, they don't really need to bring it in because the general populace is already a fat lazy bastard.