bite-sized sponge cakes
Small, round, sweet sponge cakes, often sold at festivals or as street food. The name is wasei-eigo from 'baby' and 'castella'.
wasei-eigo (Japanese-coined English), from baby castella
I bought some baby castella at the festival.
Wasei-eigo from English 'baby' and Portuguese-derived 'castella' (カステラ). The term refers to small, bite-sized sponge cakes, not actual baby food.