Wash and rinse 150 g of white rice.
Soak the rice overnight or at least 12 hours in the refrigerator.
Prepare 220 ml of drinking water, set aside 1 tablespoon, you will use the water to dissolve yeast later. Drain soaked rice and discard the water. Add in 60ml of water and process the rice until fine using blender, it takes about 3 minutes using high speed.
Mix 70 g light brown sugar, 20 g brown sugar and the remaining water, heat the mixture and stir until all sugar has completely dissolved, stop when the temperature reach about 70°C or small bubbles start appearing.
Mix hot sugar syrup and rice batter, stir and mix well.
Strain the rice mixture, place it in water bath to cool it to room temperature, about 30°C. If the mixture is too hot, you will damage or kill the yeast.
Add instant yeast to 1 Tbsp of water set aside earlier, stir until fully dissolved. Add to cooled rice mixture, mix well. Make sure the rice-sugar mixture is cool completely before adding the dissolved yeast.
Proof the mixture for 3 to 3 ½ hours in microwave oven or oven with 1 cup of hot water in it. This helps speeding up the fermentation process.
Oil the cake mold (8 inch, 20.5cm) and steam for 16 minutes over medium heat. Stir the mixture before pouring in the mold. Note: Steam with bamboo steamer as the bamboo cover will absorb the steam. Cover the lid by tying with a piece of cloth if it is made with other material. If water droplets condense on the lid and drop onto the cake, it would make the rice cake soggy.
Cool the cake before unmolding; this traditional steamed rice cake is normally served during breakfast