Beat the eggs and add the powdered sugar, beat again. Add the baking powder, vanilla sugar and rum. Beat once more and gradually add the flour.
Once the flour is dissolved, add the ground walnuts and stir. Pour the mixture into a buttered oven dish with baking paper.
Bake in a preheated 356°F (180 °C) oven until ready.
Add the cream cheese mixture to the confectionery cream and stir with a spoon. Once the cake cools, cut it into 2 layers.
Smear the lower one with the cream mixture and place the upper cake layer on top. Sprinkle with ground walnuts.