Botan dōrō is a type of Japanese dessert that is made with sweet red bean paste wrapped in a soft jelly made from agar. Think of agar like gelatin, but made from a type of seaweed instead of animal parts.
To make botan dōrō, first the red bean paste is made by boiling and mashing up red beans with sugar until it becomes a sweet and thick paste. Then, the agar jelly is made by heating up agar flakes in water until they dissolve and create a thick, clear liquid. This liquid is then poured into molds and allowed to cool and set.
Once the jelly has set, it is carefully cut into small cubes and the red bean paste is wrapped around them. The red bean paste acts like a coating around the jelly cubes, giving them a soft and sweet outer layer.
Botan dōrō is often served in Japan during the springtime and is named after the peony flower (botan), which is said to bloom around the same time.