Mix the butter and both types of sugar until creamy. Mix the egg yolks and cream into the butter and sugar mixture. Mix the flour and baking powder and stir in. Spread on a baking sheet lined with baking paper. Pre-bake in the preheated oven for approx. 15 minutes (electric stove: 180 ° C, gas: level 2, convection: 160 ° C).
Covering:
Separate the eggs, beat the egg whites until stiff. Mix the quark, both types of sugar, flour, baking powder and pudding powder until smooth. Fold in the egg whites. Spread on the pre-baked base. Sort the blueberries and spread them on the quark topping. Bake at the same temperature for about 30 minutes.
Meringue topping:
Beat egg whites until stiff. Let both types of sugar trickle in. Take the baking tray out of the oven. Spread the egg white on top. Put the tray back in the oven and bake for another 20 minutes, until the meringue is light brown. Then let it cool down.
Decorate:
Cut the cake into pieces to serve. Whip the cream until stiff and decorate the pieces with it. Garnish with blueberries and mint.