Quickly mix flour, icing sugar, butter and egg with the dough hooks of the hand mixer. Work into a smooth dough with your hands, wrap in cling film and chill for approx. 30 minutes. Roll out the dough on a floured work surface (approx. 32 cm Ø) and line a tart mould (26 cm Ø, lift-off base) with it. Prick the base with a fork and chill. Wash, halve, stone and quarter the plums. Sprinkle tart base with breadcrumbs. Place plum slices close together in the mould.
Bake the tart in the preheated oven (electric range: 175 °C/ convection oven: 150 °C/ gas: level 2) on the bottom shelf for about 25 minutes. Heat apricot jam and pass through a sieve. Spread plums with jam and bake for another 5 minutes. Let the tart cool down in the tin on a cake rack. Dust the edge with icing sugar as desired. Sweetened crème fraîche tastes good with it