Never been so soft before! The secret is all here and it’s really simple:
Ingredients:

5 eggs
130 g sugar
1 teaspoon salt

50 ml oil
70 ml milk
1/2 teaspoon vanilla extract
150 g flour
1 tablespoon cocoa
1 teaspoon lemon juice

Preparation:
1. Separate the egg yolks from the whites. Mix the yolks with sugar and salt.
2. Add oil, milk, vanilla extract, and flour.

3. Beat the egg whites with the lemon juice until stiff.
4. Combine the two mixtures and divide them into two bowls.
5. Add the cocoa powder to one of the two bowls and mix.

6. Assemble the cake by alternating the two batters.
7. Bake at 160°C (320°F) for 45 minutes.