Preheat an oven to 180°C
Lightly butter 3 X 9 inch cake pans and line with baking paper on the bottom and the sides.
Separate the eggs in two large mixing bowls. Egg yellow in one bowl and egg whites in another bowl.
To the bowl of egg yellows add the oil and the vanilla essence and whisk together. Now add the boiling water and whisk together until frothy.
Use a sieve and sift the flour, sugar, baking powder and cacao powder into the egg yellow mixture. Mix well until everything is incorporated.
Add salt to egg white mixture and whisk to stiff peaks.
Fold the whisked egg whites into the cake batter ensuring that it is well combined. You don't have to be gentle but do not beat the batter, only fold.
Divide the cake batter evenly between the 3 cake pans. Bake in the preheated oven for 20 minutes. The cakes are ready when you put a skewer inside the cake and it comes out clean. Never open the oven until at least ¾ of the time has lapsed.
Remove the cakes from the pans and let it cool on wire racks. Prepare the chocolate ganache while the cakes are cooling down.