Preheat oven at 180°

Grease a baking pan (I used the chiffon cake pan)

Separate yolks from egg white.

In a bowl whip the egg whites until they stiff and set aside.

In another bowl beat the egg yolks with the sugar until the mixture is light and frothy. Combine, whipping by hand with a whisk, the oil, milk and vanilla essence.

Sift together the flour, baking powder and salt and add them a little at a time to the mixture.

Add the egg whites and mix gently with movements from bottom to top.

Chop a part of the chocolate and add it to the mixture.

Pour the mixture into the pan and bake for 45-50 minutes (always do the toothpick test).

Melt the remaining milk chocolate and let it cool a few minutes.

Transfer the cake on the serving plate and pour the melted chocolate on top and spread over the top and sides with the back of a spoon.