I think it'd be cool to see Vanilish getting a split-evolution, since its real evolution is a bit boring, kind of like how we got Politoed as an alternate to Poliwrath.
Anyway, my idea is that it becomes...Ice/Fire. WHAT? Well, it'd be kind of rounder looking, but still an ice-cream cone...the bottom part is still an icicle, and then it has the "first" scoop, which is a round, snow shaped body, its face looking a bit "fatter", and it has stubby icicle arms. Then there's a partially melted, pink (strawberry flavored!) scoop on top of it (there's real-life "pink snow" called watermelon snow that's actually some sort of algae or something that thrives in the cold), its face looking a bit stretched out since it's melting an all, with a "feels good man!" smile. And, to top it off, there's a red orb on top acting like a cherry...that's also the source of its new-found fire powers. Perhaps a Flame Orb? There could be some new way to "fuse" the item with Vanilish, or something.
Same Base Stats as Vanilluxe, but bulkier , and the additional ability to learn Fire-type moves.