Pandan Butter Sponge Cupcakes (班兰奶油杯子蛋糕)

Recipe source from 蓝色小橱-班兰奶油杯子蛋糕.
Following is halved the original recipe and yielded 8cupcakes.

Recipe

Ingredients
3 egg yolk (about 55g)
20g sugar

2 egg white (about 70g)
25g sugar

40g cake flour
2tbsp corn flour

1tbsp pandan juice
15g coconut milk/evaporated milk
20g butter

Steps:
1. Preheat oven to 170C.
2. Lined muffins tray with paper casing and set aside.
3. Sift flour and corn flour together and set aside.
4. Simmer butter and coconut milk together till butter melted, stir in pandan juice and set aside.
5. With a hand held cake mixer, whisk egg yolks and sugar till pale.
6. Use a cake mixer, whisk egg whites till frothy.
7. Gradually add in sugar and whisk till soft peaks form.
8. Fold in 1/4 of meringue into egg yolk batter till blended.
9. Then fold in the rest of the meringue lightly in 2 portions until well blended.
10.Fold in flour in three portions till blended.
11.Lastly fold in pandan mixture in two portions till blended.
12.Spoon batter into paper casing till 70% full.
13.Bake in a preheated oven for 20-25mins.
14.Remove cupcakes and leave to cool on a wire rack.