castella (카스테라 빵) is a very popular sponge cake / bread in Korea many people around the world enjoy & crave!
You'll see certain Asian bakeries carry this fluffy delight and it's such a hit. The texture of this unlike any other. It's very soft, jiggly when you nudge it and so moist you can hear it if you open the cake apart. The taste of castella cake is egg-like and it's not overly sweet but sweet enough that you don't need to add icing to this unless you want to!