Magic Custard Cake Recipe

This amazing Magic Custard Cake Recipe I found at http://whiteonricecouple.com/ and I love it. This recipe is so fluffy and soft. It's so delicious and very easy to prepare it. You can make it in two combinations one is vanilla and other is in chocolate version. I hope you like it. 

Ingredients:
1/2 cup (113g) unsalted Butter
2 cups (480ml) Milk
4 Eggs, separated
4 drops White Vinegar
1 1/4 cups (150g) Confectioner's Sugar
1 Tablespoon (15ml) Water
1 cup (115g) Flour
1 teaspoon (5ml) Vanilla Extract
extra confectioner's sugar for dusting