During the 17th century calissons, diamond-shaped almond based sweets, were believed to have banished the plague from Aix-en-Provence. In keeping with tradition a special mass is held on the 1st Sunday of September at the Church of St. Jean de Malte for the benediction of the sweets. In 2015 the benediction will be held at 3 pm.
Orginally made by hand these sweets are now manufactured on a large scale using molds and cutters. When in Aix do visit the newly built Calisson Roy René factory that houses the Museum of the Calisson. http://calisson.com/en/content/8-visit-of-the-confectionary