Brown sugar caramels (including butterscotch)

I've been thinking about caramel recently, and specifically about butterscotch. I've not found much on the topic as a unique confection but came across a a reference to a butterscotch sauce in MIchael Ruhelman's "Ratio" app for the iPhone. In this, he states that butterscotch is a variation on a traditional caramel (sauce) that uses brown sugar instead of white sugar, and that it also has a significant amount of butter. The app claims that the ratio for a butterscotch sauce is; 1 part brown s

Thanks for that suggestion. I could use a Thermapen to check the temp without stirring. Another interesting development: As I was cleaning the pot from the separated batch, I saw the butter now solidified. I mixed it into the remaining butterscotch, and it mixed quite well. So I will try browning the butter, letting it solidify, then adding it after the caramel has been totally cooked. I hate to abandon that wonderful taste/smell of browned butter.