In a sizable mixing basin, combine all varieties of rice. Add water. For two days, soak.
Pour the bowl's contents into a large sieve to remove the water.
In a sizable food processor, place the soaked rice. Rice should be started grinding and continued until very fine. To get this uniformity, it took me around 10 minutes.
Halfway fill your puto bumbong steamer with water. Heat the water first, then let it to boil.
Fill each bamboo tube, or bumbong, with rice powder in the meantime. Note: To allow for easy steam passage, avoid compressing the rice.
Place each bamboo tube on the steamer once the water begins to boil quickly. Cook until steam begins to escape from the tube.
From the steamer, remove the tubing. Place the items on top of a piece of banana leaf. Butter should be spread all over, followed by freshly grated coconut and muscovado sugar.