It's named after 'pulak,' the Persian word for a small coin, because vendors pour the hot caramel into flat, coin-sized discs that shatter and dissolve on the tongue almost instantly.
Sugar, water, and vinegar are cooked into a thin caramel, flavored with saffron, dried lime, or cocoa, then poured onto a cold surface in small discs and left to harden into a brittle, quick-melting candy. Trays of it are sold by street vendors throughout Isfahan's bazaars.