Mix the ingredients: In a large bowl, combine rice flour, sticky rice flour, white sugar, and warm water. Stir vigorously for 3–5 minutes until smooth.

Prepare the flavored portion: Divide the batter into two equal portions, adding sweet potato powder to one and mixing well.

Strain for texture: Using a fine mesh sieve, strain both mixtures into clean bowls to aerate them.

Set up the steamer: Line the steamer with a wet cloth and place a cake mold inside, ensuring water is simmering.

Layer the mixtures: Pour a layer of the plain rice mixture into the mold, followed by a layer of the sweet potato mixture, alternating until all batter is used.

Prepare for steaming: Make gentle cuts on the surface of the cake and cover with a wet cloth to retain moisture.

Steam until cooked: Steam over medium heat for approximately 20 minutes, checking for doneness with a toothpick.

Cool and serve: Let the cake cool for a few minutes before slicing into bite-sized pieces.