It is "caramel", not "carmel", and it probably can be warmed to liquefy. You may not need to add cream
I am in agreement with you, Chef, but it reminds me of something I've wondered about most times that I've read the word "caramel"...
How did the contemporary English spelling come to be? I am sure I've thought about it way too much, but it's just one of those nagging things for me. So far, what I've come up with goes as follows:
It was named after Antoine Careme, and some people still spell it as caremel, though English dictionaries would advise differently. My guess is that there has been a sort of war between spelling and pronunciation, resulting in a mash-up of a more phoenetic spelling of caramel, and a persistent dialectic pronunciation of carmel. Personally, I enjoy thinking that neither (academic spelling nor dialectic pronunciation) is linguistically correct, particularly in a historical context.
My own incoherent ramblings aside, Ed Buchanan is right as well, low and slow is the way to go. Stirring will help to keep it from breaking as well, but stirring too vigorously can incorporate air into the sauce and eventually make it into a sort of melted taffy if you're not careful.