a failed attempt

a not successful pandan chiffon that I made last night, the top sink a little bit, Haiz... despite of the looks the pandan chiffon is moist and fluffy, still edible, we have for breakfast this morning. Will try until succeed, any advise for me to improve my chiffon? Would appreciate your help.

For those who wanted to try the recipe, I use Prima recipe. Enjoy :)


PANDAN CHIFFON CAKE
100 g PrimaFlour Top Flour
1 tsp Baking Powder
1 tbsp Pandan Juice
100 ml Coconut Milk
4 Egg Yolks
50 ml Corn Oil
¼ tsp Green Colouring
5 Egg Whites
¼ tsp Cream of Tartar
100 g Castor Sugar
Pinch of Salt
Instructions
Preheat oven to 170°.

Extract pandan juice from finely pounded pandan leaves and add to coconut milk.

Add egg yolk, 50 g sugar, oil, colouring and salt to the coconut mixture. Mix well using hand whisk.

Sift PrimaFlour Top Flour and baking powder and fold into mixture. Mix until smooth. Set aside.

Beat egg whites and tartar at high speed until formy. Add remaining 50 g sugar and beat until stiff.

Add 1/3 beaten egg white to the yolk mixture and mix using a hand whisk.

Slowly fold in this mixture to the remaining 2/3 of beaten egg whites.

Pour mixture into an ungreased 18cm chiffon tin and bake for about 50mins.

Turn tin over on a cake rack to cool before loosening cake.