Preheat your oven to 180 °C (350 °F) with the top and bottom heat.

In a mixing bowl, whisk the eggs, sugar, and vanilla sugar together until a creamy texture resembling soft peaks is achieved.

Gradually incorporate the oil and milk, blending the mixture until smooth.

In another bowl, combine the flour, cocoa powder, baking powder, and salt.

Gently fold the dry ingredients into the egg mixture, ensuring a smooth batter without overmixing.

Pour this velvety batter into a greased rectangular baking pan or a smaller sheet.

Bake for approximately 25 to 30 minutes, or until a toothpick comes out clean.

Allow the cake to cool completely.

For the glossy chocolate glaze, heat the cream until just boiling.

Remove it from the heat and add the chopped dark chocolate and butter.

Stir until melted and combined into a sumptuous glaze.

Drizzle the glaze evenly over the cooled cake and allow it to set before cutting.