The original cake recipe of flour, egg and sugar, was imported from Portugal around the mid-16th century and adapted to the Japanese palate.
Rice grown on the vast farmland of Isahaya is a major ingredient of the sweet, which has its origins in China. Made by coating dried rice with heated starch syrup and brown sugar.
This confection is filled with brown sugar paste, which evaporates during the baking leaving the inside hollow but not losing the rich flavor.
It takes about two hours from Tokyo's Haneda Airport to Nagasaki Airport. From there, take the Nishi Kyushu Shinkansen to Isahaya and Ureshino. A park near Nagasaki Airport has a stunning beach with recycled glass mixed in its sand.