For the bánh bò: Mix the yeast and flour together. Gradually add water and knead for 20 minutes until the dough is no longer sticky.

Cover the dough with plastic wrap and let it rise in a warm place for 1 hour. In the meantime, heat the coconut milk and sugar together until the sugar dissolves. Be careful not to let it boil over.

Bring water to a boil in a steamer. Place the molds in the steamer and steam for 5 minutes to preheat. Open the steamer and pour the batter into the molds. Steam for 10-15 minutes, depending on the size of your steamer and molds. The cakes are done when a toothpick inserted comes out clean and the inside is not wet.

Use a skewer to remove the cakes from the molds. Let them cool and serve with sesame salt for dipping. You can also serve with caramelized coconut milk if desired.