Once the rice batter is steamed, remove the container and flip the dough onto a surface dusted with roasted soybean flour. Wearing disposable gloves, shape the dough while it's still hot into a rectangular shape.
Coat both sides of the dough with a layer of roasted soybean flour to prevent sticking and enhance the flavor.
Roll out the dough using a rolling pin to about the thickness of a coin.
Evenly spread the prepared red bean paste over the dough. Adjust the amount of paste to your liking, adding more for a sweeter taste.
From one end, tightly roll up the dough, making sure to roll it as tightly as possible to avoid loose spots. Once rolled, gently adjust the shape with your hands to make sure the roll is evenly thick throughout.
Cut the rolled dough into even segments using a piece of string. Be steady while cutting to ensure neat, uniform pieces.
Finally, dust each piece with more roasted soybean flour to enhance the flavor.