Beat eggs, sugar and vanilla sugar until frothy. The crowd must have a good standing.
Mix the flour, cornstarch, cocoa and baking powder and sift.
Carefully mix in the flour with a wooden mixing spoon (preferably with a hole).
Pour into a springform pan lined with baking paper.
Bake at approx. 160 ° C for about 30-40 minutes, depending on the oven. After baking, turn the base with the springform pan onto a wire rack and allow to cool.