Nagasaki Castella Cake — Portuguese Sweet Perfected in Japan

Castella (カステラ) is a sponge cake introduced to Nagasaki by Portuguese merchants in the 16th century. The Japanese version evolved into a distinct form: denser than European sponge cake, sweeter, and with a characteristic golden-brown top and bottom crust. Fukusaya, established in 1624, is the oldest castella maker and maintains the traditional recipe: just eggs, sugar, flour, and rice syrup (mizuame), whipped by hand for 30 minutes to create the specific density.

Nagasaki has 30+ castella makers, each claiming recipe variations. The standard presentation is a long rectangular cake sold in wooden boxes — traditionally given as formal gifts. Eating fresh castella from the actual bakery, where the cake is still warm from the oven, is a completely different experience from the packaged gift version.