“You have to try this one,” I said, pointing to the little green pastry in the display cabinet. My family looked unconvinced. They had sensibly ordered cannoli. I had chosen something called Fedda del Cancelliere — The Chancellor’s Bottom. Not exactly the sort of name you expect to find inside a convent. Hidden within Palermo’s former Convent of Santa Caterina d’Alessandria is a small confectionery bakery where centuries-old recipes have quietly found their way back to life. The convent itself is magnificent, but it was the pastries that had drawn me there. Long before cafés lined the city’s streets, cloistered nuns were creating elaborate sweet treats behind these walls, selling…