Mix sweet rice flour, sugar, and salt in a bowl until well combined.
Sift in cocoa powder and mix thoroughly.
Gradually add warm water and mix to make a dough.
Line a steamer with parchment paper and place the dough inside.
Evenly sprinkle red beans or chocolate chips on top.
Steam in a preheated steamer for 20 minutes.
Let it cool, then cut into bite-sized pieces.