I could care less.
Fine, if you wish to be illogical. By saying you could care less, you're stating that you care somewhat and there's room to care less. OTOH, if you say you could not care less, then you're stating that you cannot possibly care at all.
It's a stupid expression that has unfortunately wormed its way into the language.
I realize, though, that there is a possibility that you're being sarcastic. Good. Be that way.