Smooth out the texture of the amazake with a mortar and pestle, or in a food processor. Sift together the flour and baking soda.
Beat the eggs and combine with the mirin and amazake. Add the flour and baking soda, then briskly mix with a whisk. Let sit for about 15 minutes.
Pour oil into a frying pan, heat until steam rises, then place the pan on top of a damp kitchen towel and allow to cool. (Skip this step if using a Teflon coated frying pan.)
Turn the frying pan on low heat, then pour 2/3 of a ladle full of batter. (it will create a nice circular shape if poured at a slightly high distance from the pan.)
When the surface starts to bubble and dry, then flip over. (If it browns lightly, the heat is low, and if it browns to a dark color, then the heat is high. Adjust to desired temperature.)
After both sides are browned, the pancakes are complete. Bake 12 pancakes in the same way. Cool on a rack. Cover with a kitchen towel so that they do not dry out.
Divide the tsubu-an into 6 parts, then spread on one pancake and sandwich with the other. Make 6 dorayaki in the same way.
Adjust the shape while wrapping in plastic wrap to give them a nice shape, and give a moist finish to the pancakes. If you have time, it's best to let them sit in plastic film before serving.
Story Behind this Recipe
These days, I often make tsubu-an (chunky sweet adzuki bean paste), so I thought of thinning it to use as a sauce for amazake pancakes (Recipe ID: 2102914). But then, I decided that it would be quicker to use it as is to make dorayaki, and came up with this recipe. It was a hit even with kids that don't like amazake.
You can use baking powder as a substitute for baking soda, but increase the amount to 1.5 teaspoons. The weight of the batter will depend on the type of amazake. If the batter appears heavy, dilute with water. It should smoothly pour off of the whisk or ladle.