When the Spanish encountered cacao in Mexico in the early 16th century, Barcelona became an important transit point for the ingredient when it arrived in Europe. But xocolata, as processed chocolate is known in Catalan, didn’t become mainstream in the city until a couple hundred years later. Eventually, the ingredient came to be included in dishes both savory and sweet, and Barcelona gained a strong reputation for both its chocolate consumption and production. In particular, Carrer Petritxol, in the city’s Gothic Quarter, became home to several chocolate shops, lending the…