I've just used the end of a small, unmarked bottle brought from Italy by a friend (an Italian expat). It was wonderful, thick, syrupy, and I've become addicted to drizzling it over good parmesano reggiano as a snack. His sister evidently married into a family that's been producing it for their own use for more than a century and he shared some of theirs. I'm hooked.
What should I buy? Where can I get it? I'm in a Philly suburb. Am willing to spend on it. Thanks!