Wash, de-stem and stone plums. Grease a tart tin with a removable base or springform pan (26 cm Ø). Mix flour, baking powder, 200 g sugar, lemon peel, 1 pinch of salt, egg yolk and fat in pieces, first with the dough hooks of the hand mixer, then briefly with your hands to form crumbles
Spread about 2/3 of the crumble in the mould, press up about 2 cm at the edge and press down at the bottom. Spread the plums on the base. Sprinkle the rest of the crumble and then 5 tablespoons of sugar on top. Bake in the preheated oven (electric cooker: 175 °C/circulating air: 150 °C/gas: level 2) for about 50 minutes. Let them cool down