1. Heat the coconut milk, add it to the temperature, then fire, add butter to melt; when the coconut milk is cool to the hand temperature, add yeast powder, mix well;
2. Add the cassava powder and stir it into a paste; use a container without water or oil to fill with eggs and sugar;
3. Use electric egg beater to quickly beat until the volume expands;
4. Add the cassava paste made in step 3, and continue to mix it evenly with the mixer at medium speed;
5. Put it in a warm place and ferment for 100 minutes, in which, every 15 minutes, use the electric eggbeater to stir it at a medium speed for 30 seconds;
6. Take another container, spread butter on the inner wall, pour in the fermented cassava paste, keep it in the warm place for 1 hour;
7. Steam in high heat for 20 minutes, then cool the parts.