Prepare the Batter: In a bowl, break the eggs, add vanilla and sugar, and whisk for about 5 minutes until fluffy.
Add Wet Ingredients: Slowly pour in the oil and milk while mixing.
Combine Dry Ingredients: Turn off the mixer and sift in the flour and baking powder, along with a pinch of salt. Mix until incorporated.
Add Chocolate: Roughly chop the leftover chocolate and fold it into the batter.
Bake: Transfer the mixture to a greased and floured 24 cm mold. Level the surface and bake in a static oven at 180°C for about 45 minutes.
Cool and Serve: Once baked, let it cool slightly before removing from the mold. Allow to cool completely before serving with a dusting of powdered sugar.