Grease a fat pan (approx. 32 x 39 cm; approx. 3.5 cm deep) and dust with flour. Wash, halve and stone the plums. Mix cinnamon and 25 g sugar.
Separate 3 eggs, chill the egg white. Cream fat, 200 g sugar, vanilla sugar and 1 pinch of salt with a hand mixer. Stir in 4 eggs and 3 egg yolks one after the other. Mix flour, starch and baking powder and stir in portions briefly.
Add 75 g brittle.
Spread the dough on the fat pan. Spread plums on top. Sprinkle with cinnamon sugar. Bake in the preheated oven (electric cooker: 200°C/circulating air: 175°C/gas: level 3) for about 35 minutes.
Beat 3 egg whites and 1 pinch of salt until stiff. While continuing to beat, add 150 g sugar and continue beating until the sugar is completely dissolved. Pour into a piping bag with a large star-shaped spout.
Take the cake out of the oven. Spray about 24 meringue tuffs on top and sprinkle with 25 g brittle. Continue baking at the same temperature for 10-15 minutes. Cool down.