Grease a fat pan (approx. 32 x 39 cm; at least 3.5 cm deep). Whisk butter, sugar, vanilla sugar, 1 pinch of salt and lemon zest with the whisk of the hand mixer for approx. 7 minutes until creamy.
Stir in the eggs one by one. Mix flour, almonds, starch and baking powder and stir in briefly, alternating with the milk.
Spread the dough on the fat pan. Spread the berries with a teaspoon as a blob. Bake in the preheated oven (electric cooker: 175 °C/circulating air: 150 °C/gas: level 2) for about 30 minutes. Let them cool down.
Dust the cake with icing sugar.