Oriental sweets. Confectioners of Syros learned the art of pastry from Asia Minor and Chios. They learned the art of pastry by people who came from two places famous for their syrup desserts. So over time the sweets were made known throughout Greece and beyond.
Mastichaki, galaktoboureko(custard pie with phyllo/fillo and syrup), pastry, baklava, are absolutely must try and will probably buy to taste and offer your friends back home.