【 カステラ・kasutera 】castella cake
カステラ is a sponge cake made from flour, eggs, sugar, and 水飴 (みずあめ mizuame) which is a thick, clear liquid sweetener made from starch (common in wagashi). The name and recipe come from pão de Castela (Portuguese bread) and pão de ló (Portuguese cake). The Portuguese brought this cake to Japan (Nagasaki) in the 16th century.
For this, カステラ is a specialty of 長崎 Nagasaki.
From the Meiji era, カステラ producers started adding みずあめ to the recipe, making it moist and the カステラ it is today.
しっとり (shittori) = moist
ふわふわ (fuwafuwa) = fluffy