| Tiramisu Kit Kat
YUMMY!
I don't think these are typically available in the US, though you may be able to find them in Asian specialty stores.
Japan produces seasonal Kit Kats; usually two different flavors every few months. Most recently, they had blueberry and tiramisu. I was placing an order from Japan for some learning supplies, and figured I'd order the tiramisu. Oh my goodness, they are so good.
In the past, I've had green tea Kit Kats, dark chocolate, strawberry, cherry, and white chocolate (I think they've been available here, too). All have been really good.
Long story short, if you have a friend in Japan, or are on vacation in Japan, or have cause to order something from a place that also sells these Kit Kats, it is worth it to ask for/buy a box or two. | 
