Are you thinking perhaps of Butter Rum Lifesavers? Which are basically pretty butterscotchy, but have, amazingly, a teeny tiny hint of rummish flavour? Also, they’re like, awesome?
According to the Wrigley’s website, you can also get a “Butter Toffee” sugar-free version in peg-bag format.
I’ve got no idea where you’d buy them though :/ I mean, they’re definitely still around, but I live in the UK and buy them from an import store, and most of the results I could find online were to buy in bulk. Anyway, good luck!