Drain blueberries well. Grease baking tray and dust with flour. Preheat oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Finely dice marzipan. Score the vanilla pods lengthwise and scrape out the pulp.
Cream the marzipan paste, the vanilla pulp, 375 g butter in flakes, 125 g sugar and 1 pinch of salt with the whisks of the mixer. Stir in 6 eggs one after the other. Mix flour and baking powder and stir in with the milk.
Put the dough on the baking tray and smooth it down. Spread blueberries on top. Bake the cake in a hot oven for 15-20 minutes.
Beat 4 egg whites until stiff, adding 140 g sugar and vanilla sugar. Remove the cake from the oven. Spread meringue on top. Bake at the same temperature for 10-15 minutes. Remove the cake and let it cool down.
Cut into pieces. Whipped cream tastes good with it.