Beat eggs, sugar, vanilla sugar and salt until light and fluffy.
Fold in the flour to make an airy, thick sponge mixture.
Spread half of the batter evenly on a baking sheet lined with baking paper and bake the sponge cake in a preheated oven at 190 °C top and bottom heat for about 10 minutes.
Meanwhile, spread the remaining batter on a second baking sheet lined with baking paper and bake the second sponge cake directly after the first one, also at 190 °C top and bottom heat, for about 10 minutes. Let the two sponge cakes cool down.
Line the salad bowl with plastic wrap so that the wrap hangs outward.
Cut sparingly, at the edge of the sponge cake layers three circles in the size of approx. Ø 18 cm, Ø 16 cm and Ø 14 cm each.
Cut the leftover sponge cake layers into long strips about 3 cm wide.
Spread the sponge cake strips close together in the salad bowl so that the bowl is completely covered with them (see pictures at the top of the post), and then cut off the ends of the sponge cake strips that are above the edge of the bowl.
Gather the sponge cake scraps, wrap them in an airtight container, and set them aside for now.