Dissolve the sugar in the water by heating it in a small pot. Set aside to cool down to room temperature.
Mix the yeast with warm water. Set it aside to bloom (usually in a few minutes).
Add the rice flour and sugar water to a large bowl. Mix until well combined. Add in the yeast mixture and lightly stir to combine. Cover and let it proof for 2-3 hours in a warm environment. *Add a few drops of oil 30 minutes into the proofing step.
Once a thick layer of small bubbles are on the surface of the rice mixture, lightly grease a 9 inch pie pan. Then add the rice mixture to the pan.
Boil the water for the steamer first. Add the pan to the steamer. *Cover with the lid and let it steam for 10-15 minutes.
Remove the pan from the steamer and let it completely cool down. Remove the cake from the pan and slice into diamonds, wedges, or cubes. Serve and enjoy!