After stirring and melting the butter in insulated water, let it cool for later use.
Add enough water to the steamer and turn on the heat to preheat the steamer.
Prepare cake mold and place baking paper on the bottom for later use.
Cut small pieces of pandan leaves into a blender, add water and blend to make a juice. If unable to blend, add a little more water slowly.
Filter out the fiber of pandan leaves with a cloth or a strainer.
Add 50 grams of pandan juice to the butter, add a little salt to enhance the flavor, and stir well.
Separate the yolks and whites of the eggs, and put the yolks in a bowl of butter. Put the egg whites into a large bowl that is free of oil and water.
Stir the egg yolks evenly.
Add sifted all purpose flour, corn starch and milk powder, and mix well.
Add lemon juice or white vinegar to egg whites.
Beat with a whisk at high speed until there are large bubbles formed, add 1/3 fine sugar, and then continue to beat at high speed.
After the bubbles become thinner, add 1/3 fine sugar, and then continue to beat at high speed.
After the bubbles are finer, add the remaining fine sugar, and continue to beat until stiff peaks.
Scoop the meringue into the egg yolk batter in 3 portions and mix well.
Pour the evenly mixed batter into the mold, tap it a few times to knock out the large air bubbles.
Put it in a boiling steamer. Close the lid diagonally to leave a gap, steam on medium heat for 55 minutes, then turn off the heat and leave for for 5 minutes.
After steaming, use a knife to cut along the edge of the mold, pull out the baking paper and cut it into the size you like.