Drain the mandarin oranges. Mix the butter, 150 g sugar, vanilla sugar and half of the lemon zest until creamy. Mix in 3 eggs alternating with 50 g flour, mix 200 g flour with baking powder, fold in briefly. Spread the dough on a baking tray and cover with tangerines and berries.
Separate 7 eggs, remove 3 egg whites and refrigerate. Mix together 170 g of sugar, egg yolks, custard powder and the rest of the lemon zest. Beat 4 egg whites and 30 g sugar until stiff. Raise the egg whites under the curd mixture and spread over the berries. Bake in the preheated oven at approx. 175 ° C top / bottom heat for approx. 25 minutes.
Beat 3 egg whites until stiff. Sprinkle in the remaining sugar and whip until it is very stiff. Stir in lemon juice. Spread the meringue in the form of a blob on the curd mixture and bake for another 10-15 minutes. Let cool and serve.