So this all sounds pretty simple right? The trick, it seems, is to make a caramel that doesn’t harden into a rock when it cools. (We’re still working on it. Though happily. What better recipe to have to make over and over again?) Even if it does harden, not a problem. When you’re ready to use it, just put the jar in the microwave for 30 seconds to a minute and it will be back to liquid. Repeat as often as necessary. When the jar has been licked clean, return to step #1.