For the short pastry, quickly mix flour, butter in flakes, 60 g sugar, vanillin sugar and egg with the dough hooks of the hand mixer to a smooth dough. Wrap in foil and chill for about 30 minutes. In the meantime clean, wash, halve and stone the plums. Bring 200 ml juice, 100 g sugar and cinnamon to the boil. Add plums and steam for 2-3 minutes. Mix pudding powder and starch with 100 ml juice until smooth.
Remove from heat, stir in the starch and simmer for about 1 minute while stirring. Take out the cinnamon stick. Put the pot aside and let the plums cool down. Roll out the short pastry on a well floured work surface and make it round (32 cm Ø). Line a greased and floured springform pan (26 cm Ø) with the pastry, pressing the rim. Prick the pastry base several times with a fork. Spread plum compote on top and smooth it down. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) on the lower level for about 1 hour. After 3/4 of the time beat egg white and lemon juice until stiff. At the same time, pour in 100 g sugar. Beat the beaten egg whites until the sugar is completely dissolved and shines white. Remove the cake from the oven.
Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) on the lower level for about 1 hour. After 3/4 of the time beat egg white and lemon juice until stiff. At the same time, pour in 100 g sugar. Beat the beaten egg whites until the sugar is completely dissolved and shines white. Remove the cake from the oven. Spread the meringue mixture on the compote in a wavy shape and bake at the same temperature for 15 minutes. Take the cake out of the oven, place it on a cake rack and let it cool down for about 2 hours. Sprinkle with pistachios and decorate with mint