How to make super soft chocolate cake

Recipe:

A

3 egg yolks

30 g sugar

60 g self rising flour/cake flour

20 g cocoa powder

40 g olive oil

60 g water

B

3 egg white

30 g sugar

1 teaspoon corn flour

Procedure:
1. Beat egg yolks with sugar using fork or hand mixer, add in olive oil.
2. Mix cocoa powder with water, then add into the previous mixture.
3. Add in flour, mix well.
4. Beat egg white, with sugar and corn flour, until stiff peak.
5. Pour 1/3 of the egg white mixture into egg yolk mixture, fold in, then pour to the rest of the egg white, and fold slowly until well mixed. Do not overmixed!
6. Preheat oven at 170-180 celcius.
7. Pour the mixture in a pan.
8. Bake for about 18-20 minutes.
9. Insert a toothpick into the centre of the cake, if it's still wet, it needs more time, if it comes out clean, that means the cake is ready.