Grease a fat pan (deep baking tray; approx. 32 x 39 cm) and dust with flour. Wash the plums, remove the stalks, halve and stone them.
Orange hot wash and dry, the peel rub off. For the crumbles, briefly knead 300 g flour, 150 g sugar, 1 packet of vanilla sugar, 1 pinch of salt, 1 egg yolk, half the orange peel and 175 g butter in flakes using the dough hooks of the mixer.
Then quickly work into crumbles with your hands.
Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer). For the sponge mixture mix 200 g butter, 175 g sugar, 1 packet vanilla sugar and 1 pinch of salt with the whisks of the mixer until creamy.
Stir in 5 eggs one by one. Mix 375 g flour, almonds and baking powder and stir in.
Put the dough into the fat pan and smooth it down. First spread the plums and then the crumbles evenly on top. Bake in a hot oven for about 35 minutes. Remove and let cool on a cake rack.
Whipped cream with the remaining orange peel tastes good with it.