One of the great things of Japanese festivals of a certain size is the fast food sold there. From very simple grilled meat – on sticks – and very elaborate pancakes with different toppings – rolled around sticks – to the all time favourites of yakisoba and okonomiyaki. Sweets are either caramelised fruit like apples or strawberries – on sticks – or bananas – on sticks – dipped in chocolate and sprinkles.
And then there are Kasutera. They are hard to describe, little oval balls made from simple pancake batter (I think) and baked in a special mold. They are not very sweet as there is no sugar added (although is there certainly some in the batter), and they are best when eaten fresh and really hot.
Baby Kasutera like this seem to be a speciality of matsuri, I have never seen them sold elsewhere. Also it seems that at least in Kyoto there is a monopoly on Kasutera. No matter what festival, and no matter how large, there is a single Kasutera booth only and it is always the same company. So, if you come visit a Kyoto festival, try to find the Kasutera booth, they are certainly worth it!
By the way, there is also a sponge-like cake called Kasutera, but the taste is a bit different. Don’t mistake those two, although the Kasutera cake is not usually sold at matsuri anyway.