Knead the flour, butter, sugar, egg and salt. Wrap the shortcrust pastry in cling film, cool for about 30 minutes.
Peel the pineapple, cut eighths and cut out the stalk. Cut the pulp into slices about 1 cm thick.
Separate eggs. Mix egg yolks, quark, sugar, vanilla sugar, lemon zest, flour and lemon juice. Beat egg white and cream separately until stiff. First fold the cream, then the egg whites into the curd mixture. Spread the mixture on the shortcrust pastry and place the pineapple pieces decoratively on top. Bake the cake in the oven at the same temperature for about 30 minutes. Let cool and dust with powdered sugar just before serving.