Pandan chiffon cake

Ingredients:
5 egg yolks
20 gm caster sugar
100 gm cake flour
1 tsp baking powder
100 ml coconut milk
2 Tbsp pandan juice (see below for making pandan juice)
a few drops pandan essence/pandan paste, optional
3 Tbsp olive oil
Ingredients of egg whites:
5 egg whites
60 gm caster sugar
½ tsp cream of tartar
Ingredients of pandan juice:
10 pandan leaves, fresh or frozen
1½ Tbsp water

Method:
Preheat oven to 170C (338F).
Beat the egg yolks with a balloon whisk and mix in 20 grams of sugar. Add coconut milk, pandan juice, and a few drops of pandan paste (if desired). Combine well.
Sift in cake flour and baking powder in three batches into the egg yolk mixture. Mix well. Lastly, add olive oil. Set aside.
Use a large clean bowl, making sure there’s no water or oil in it. Beat the egg whites with an electric mixer until bubbles form. Add the cream of tartar. After mixing well, add the 60 grams of sugar in three batches, about one-third at a time, and beat well between additions. Continue to beat until stiff peaks form. (Note: please refer to this video “How To Beat Egg Whites”.)
Spoon out 1/3 of the beaten egg whites and fold into the egg mixture. Lightly fold in the rest of the beaten egg whites with a spatula, until just combined. (Note: please refer to this video "How To Fold-in Egg Whites.)
Pour into the cake pan and bake in preheated oven for about 35 to 40 minutes. After baking the first 15 minutes, if you find your cake gets browning, reduce heat to 150C（300F）, continue to bake until cooked through. A needle comes out clean when inserted in the middle.
Remove cake from the oven. invert the pan immediately. Allow it to cool completely.
To make pandan juice:
Chop pandan leaves into chunks, pop in a food processor and add about 1½ tablespoons of water. Process to small pieces.
Place pandan leaves in a muslin bag and squeeze out the juice. You need about 2 tablespoons of it to make this cake. If you don’t have a muslin bag, just use your clean hand to squeeze out the juice.

Notes:
I added a few drops of pandan essence so the cake is in light green.
If you want a totally natural pandan cake, just skip the pandan essence. Your cake would look a bit light yellowish, not bright green though.