A few years ago, Gavan MacBane did some impressive, archaeology-based research on medieval sugar processing in Cyprus. He presented at Pennsic a couple times - he even brought a "sugar loaf" shaped like, well, a sugarloaf. His article is in the Florilegium, with pictures:
http://www.florilegium.org/files/FOOD-SWEETS/Cypriot-Sugr-art.html