Separate the egg whites from the yolks. Beat the egg whites with the salt and in another container, beat the egg yolks with the sugar until it becomes a fluffy cream. Add the milk and oil to the egg yolks and mix with the beaten whites.
Add the sifted flour with baking powder, then the cocoa lastly. Finally, stir the mixture with the broken chocolate and rum. Pour it into a greased and floured form with a hole with a diameter of 10 1/4″ (26 cm).
Put the cake with chocolate pieces in a preheated 356°F (180 °C) oven to bake for about 25-30 minutes. Check its readiness with a wooden stick. Let the finished cake cool and sprinkle it with grated milk chocolate.