No yeast or preservatives needed. Just add in the ingredients to the same amount as the egg, and mix together. It's super simple. (1:1:1:1)
How you make these will change based on the size of the egg, so if everything is in proportion to the egg, you can make a delicious treat without fail. Kitchen scales are rather convenient!
You can reduce the sugar and butter by about 5~10 g if you like.
Enjoy Japanese food around the world.