Castella

Castella ("Kasutera" in Japanese) is a sponge cake produced in Japan. It is made of sugar, flour, eggs, and starch syrup, very common at festivals and as a street food.
It was originally produced in Portugal during medieval times, and when the Portuguese reached Japan they gave some of it to the Japanese nobility. The name is derived from Portuguese "Pão de Castela" which means "bread of Spain".