Put coconut milk and milk with lemongrass stalk, lime leaves, and pandan leaves in a saucepan. Bring to simmer while keep stirring with a spatula.

Turn off the stove. Sieve the coconut milk, set aside, and let it cool completely.

Put 65 gr flour, 100 ml warm water and 5 gr instant yeast in a bowl. Mix with a spatula until well blended. Cover with cling wrap, let the yeast work for 15 minutes.

After 15 minutes, the yeast mixture should be bubbly. If not, you need to redo again, the yeast is probably expired.

In another bowl, put in egg yolks, sugar, salt, and vanilla powder or extract. Mix until the sugar dissolves or the batter is quite pale.

Put in the tapioca flour into the egg yolk mixture. Blend well. Transfer the bubbly yeast mixture into it. Mix well.

Pour in coconut milk mixture in parts. Mix with low speed.

Cover with cling wrap, let it ferment for at least 2 hours.

After 2 hours, stir the batter until the bubbles are gone.

Preheat the oven and put the baking pan to preheat it too.

Pour the batter into the hot baking pan. Bake at the lower rack of the oven with only lower heat 190°C for 40-50 minutes.

Check with a bamboo stick to see if it is done.

After that, move the pan to the middle rack, turn on the upper heat 180°C for 5-10 minutes.

Please always check the top to prevent it overly done. When it is a little brownish, it is enough.