Yatai Sweets: Baby Castella Mini Cakes
Always fresh and hot and sometimes Doraemon
Castella is Japanese sponge cake. It is one of the foods popular as omiyage souvenirs and gifts. Baby Castella don't make fancy gifts, but they are fun. Fresh, hot, and baked in front of you, I think they are one of the best sweet foods from yatai food stalls.
Castella is made with simple ingredients, usually honey, eggs, milk, and flour. The baby versions taste a little like fresh waffles or pancakes, but come in a lot more shapes. Basic ones are round, but I have also seen Doraemon and his little sister Dorami, Anpanman and his friend Dokinchan, and Pikachu being baked. I think you can also eat baby Donald or Hello Kitty.
When you visit a festival at a shrine or temple, look for the yatai food stalls and see what you can find. If you want to search for more images, also try the Japanese spelling ベビーカステラ (bebi kasutera).
Can't find Doraemon baking? Eat Tokyo Skytree!
Although not from a food stall, I would like to introduce this: small Tokyo Skytree cakes. These are sold exclusively at the Tokyo Skytree branch of Brothers Patisserie in the Solamachi shopping mall. Of course the famous tower comes in plain and macha flavor. After all, this is a Japanese cake.