For one thing, I believe there is such a recipe under the cider recipe subforum. I know there's one for a caramel apple mead, but that takes over a year, which is a long time to wait. Based on reading that one, and the caramel apple cider recipe I believe is kicking around though, it sounds like in order to get an enduring caramel flavor you'd want to use some Crystal 60L or 120L. I remember there was some debate about whether caramel would ferment out or not. Brown sugar definitely will. This sounds like a cider that could be great tasting if you left it still and backsweetened it, or did so then carbed up in a keg. Bottle carbing is difficult.
Also, if you are willing to let it age for 9 months, the caramel apple mead is a cyser that you might want to check out, under the mead recipes, this one is by summersolstice.
I'm sure others with more experience can be of more help though.