Clear water cake (sponge cake)

(A)
- 3 egg yolks
- 1 whole egg
- 50g corn oil

(B)
- 50g low protein flour (cake flour)

(C)
- 3 egg whites

(D)
- 50g castor sugar
- Dash of salt

* Notes from The Little Teochew:
1. I used my vanilla sugar because I wanted a hint of vanilla in my cakes ... people who do not like a strong, eggy smell should add 1/4 tsp vanilla extract;

2. I used Top Flour instead of Cake Flour;

3. I used regular canola oil in place of corn oil ... any neutral-flavoured vegetable oil can be used;