80gwater(plus 200g, divided; note that when measuring water, g = ml)
100gwhite granulated sugar(1/2 cup)
3gactive dry yeast(about 1 teaspoon; can substitute instant yeast)
30glukewarm water(30 ml; about 2 tablespoons)
vegetable oil(for brushing)
In a heat proof mixing bowl, mix the rice flour with 80g (80 ml) water to form large clumps. Set aside.
In a small pot, add the sugar and 200g water. Bring to a boil and stir just until the sugar is completely dissolved. Turn off the heat and immediately pour the boiling sugar water into the clumped rice mixture. Whisk for a few minutes, until smooth (there should be no lumps). The mixture will look like a thin batter. Cool until lukewarm.
While the mixture is cooling, dissolve 3g active dry yeast (or instant yeast) into 2 tablespoons lukewarm water. Let stand for 15 minutes so the yeast can bloom.
When the rice mixture is lukewarm and the yeast has activated, stir the yeast mixture into the batter and whisk for 3 minutes.
Cover the bowl with an overturned plate, and allow it to ferment in a warm place for at least 3 hours. I left mine inside the microwave with a large mug of boiled water sitting next to it and the door closed. After each hour, I replaced the mug of water with another mug of boiling water to keep the environment warm.
In the last 10 minutes of fermentation, prepare your steamer, and make sure there’s enough water in it to last for 20 minutes of steaming over high heat.
After the 3 hours of fermentation are complete, you’ll see foamy bubbles have formed on the surface of your batter. Turn on the heat to boil the water in the steamer.
Pour the rice mixture into a 8" to 9" pie pan or other shallow heatproof dish that will fit inside your steamer. When the water is at a rolling boil, carefully place the dish into the steamer, cover, and steam for 20 minutes on high heat.
After 20 minutes, turn off the heat but do not uncover the steamer. Let the cake rest for 2 minutes. After 2 minutes, you may open the lid and remove the cake from the steamer.
Brush the top of the cake lightly with vegetable oil to give it a nice shine and keep it moist. Allow it to cool on the counter before cutting. Brush your knife with oil before slicing. Serve.
Store in an airtight container in the refrigerator (during spring/summer) or on the counter (fall/winter). I enjoy these cold or at room temperature, but if you want to reheat them, simply steam for 5 minutes.