This is the top-selling cookie at Bobette and Belle, owing in part to the intensely dark chocolate flavour but also to the contrasting texture and taste of the fleur de sel garnish on top. Salty-sweet combinations have been very popular in the past years, but the addition of fleur de sel to sweets is a longstanding tradition in French pastry. Salt enhances flavour, this is particularly true when it’s paired with dark chocolate. Fleur de sel de Guérande, which is often considered one of the best salts in the world, is a variety of salt harvested in coastal Brittany. Its subtle crunch and delicate flavour make it the perfect choice for garnish in this recipe, and it is well worth the price tag if you are able to find it.