1. Cut bamboo 12” long above the joint. Clean the inside and outside and turn them upside down to dry.
2. Mix coconut milk, sugar and salt to dissolve.
3. Clean the rice grains several times. Drain and mix with boiled black beans.
4. Fill the bamboo cylinders with rice mixture and tamp down by bumping them on the floor a few times. Leave about a 2-inch space on the top.
5. Pour the coconut mixture in gradually until it covers the rice.
6. Fold pandan leaves into a square and stuff them to cover the top part of the tubes. Roll the coconut husks and stuff the tubes tightly. Let set 5-6 hours.
7. Roast the bamboo on a charcoal stove. Turn them around evenly until the bamboo becomes brown (about 35-40 minutes).
8. Set aside until it cools down some. Then peel the outside skin of the bamboo to make it thinner and easier to crack and strip off when ready to eat.