Marbled Chocolate Chip Cake

Preheat the oven to 180°C (gas mark 6).
In a large bowl, beat the eggs with the sugar until light and fluffy.
Add the oil and milk and mix well.
Cake assembly:

Dust a cake pan (ball oven or deep skillet) with butter and flour.
Alternately add a layer of plain batter and a layer of cocoa paste to the pan to create a marbled effect.
Once all the batter is in the pan, sprinkle the top with the remaining chocolate chips.
Baking:

Bake for 45 to 50 minutes. Check the doneness by inserting the tip of a knife into the center of the cake: it should come out dry.
Let the cake cool before removing it from the mold.
Serve:

Serve the cake alone or with coffee or tea as a gourmet snack or dessert.