Cream butter, 200 g sugar, vanillin sugar, salt and lemon zest with the whisks of the hand mixer. Mix in the eggs alternating with some spelt flour one after the other. Mix remaining spelt flour and baking powder and stir in briefly with the cream. Quickly stir in 200 g cranberries with a spoon
Put the dough into a greased, flour-strewn fat pan of the oven (32 x 39 cm), smooth it down and spread 100 g cranberries on the dough. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 35 minutes
Whisk the egg white with the whisk of the hand mixer for about 5 minutes until stiff. Finally, pour in 100 g sugar. Put the beaten egg whites in a piping bag with a perforated spout. Remove the cake from the oven and spray 24 beaten egg whites evenly onto the cake. Bake at the same temperature for another 10 minutes. Remove from the oven, place on a cake rack and allow to cool
Dust with icing sugar