The legend says that vanilla was introduced to Europe by Spanish conquistador Hernán Cortés, who had seen the Aztec Emperor Montezuma drink his xocolatl (sort of a chocolate drink) with a bit of vanilla. The Mesoamerican flavoring gained massively in popularity in the 19th century, when botanists found a way to hand-pollinate it, which allowed for it to be grown around the world. Today, the vast majority of vanilla (some 60%-80%) comes from the African island of Madagascar, and it is the second most expensive spice (only behind saffron) in the world, mostly because it’s difficult to produce. However, at...