Line the fat pan of the oven (32 x 39 cm) with baking paper. Cream fat, sugar, vanilla sugar and salt with the whisk of the hand mixer. Stir in the eggs one after the other.
Mix flour and baking powder and stir in. Put the dough into the fat pan and smooth it down. Bake in the preheated oven (electric cooker: 175 °C/ circulating air: 150 °C/ gas: level 2) for 20-30 minutes (test with sticks!!!).
Let it cool down on a cake rack. Peel off the baking paper, cut the base in half once. Place a baking frame or firm strips of aluminium foil around each base.