If you've ever experienced the smoky, caramel-toned flavor of piloncillo, you know why it's such a treasured foodstuff.

The unrefined sweetener, commonly used in Mexican cooking, is made from sugarcane juice that has been poured into molds and hardened into blocks. Pretty to look at but hard to use, piloncillo requires a chisel or near-diamond-sharp grater to break it into manageable bits.

Leave it to Rancho Gordo owner Steve Sando to provide a solution. He has found what he calls a "magically granulated" piloncillo ($9 for 1 pound) in the Huasteca region of San Luis Potosí in northeastern Mexico, for which he is the exclusive distributor in the United States.

One fan is Paul Lemieux, pastry chef at Rutherford's Auberge du Soleil. On a recent menu, he featured bananas Foster with cajeta-crème frâiche semifreddo and piloncillo-banana vinegar gastrique. That banana vinegar ($14 for 12.3 ounces) is another Rancho Gordo exclusive.

For a simpler preparation, drizzle Lemiuex's gastrique (click here for the recipe) on vanilla ice cream, or use the piloncillo itself wherever brown sugar is called for.

Piloncillo and banana vinegar are available at Rancho Gordo's Napa store, 1924 Yajome St. (at Jackson St.), Napa; 707-259-1935 or ranchogordo.com