From the 淡交テキツト
Mix 80 gr white flour, 16 gr joushinko, 150 gr sugar with 250 gr water
Mix 5 gr kudzu with 50 gr water
Combine, then put into a baking sheet lined container, but keep about 30 gr mixture for later, steam on high for 10'
Add amanatto, and remaining mixture
The book sais to steam for another 20'; Miya prefers hers tougher, so she steams for longer.
To make amanatto, I got canned beans, got a 2:1 syrup to boil and let them cool overnight in it. That was okay, but probably to cook them in sugar is better.
➡️ Revising this recipe in III 26, I think it might be better to make a more classical 外郎 dough, and to make the amanatto with a mix of different coloured beans!