I've tried the Duncan Hines ready-made caramel frosting. If you like butterscotch...it's delicious but it tastes nothing like caramel. You might also try using caramel apple dip. That tastes so good. I've never used it as a filling but I've seen recipes where it is part of the filling (I think the Snicker's cake Dawn shared uses it).
Birthdays are just nature's way of telling us to eat more cake.
Birthdays are just nature's way of telling us to eat more cake.