Knead 250 g flour, vanillin sugar, 25 g icing sugar, 1 pinch of salt, 1 egg, 125 g butter in pieces and 1 tablespoon cold water first with the dough hooks of the hand mixer and then briefly with your hands to a smooth shortcrust pastry.
Wrap in foil and chill for about 30 minutes.
Grease a tart mould with a removable base (26 cm Ø) and dust with flour. Roll out the dough on a lightly floured sheet of baking paper to a circle (approx. 30 cm Ø) and line the tin with it.
Press the dough into the grooves so that it is approx. 1⁄2 cm above the edge. Prick the dough base several times with a fork. Chill for about 15 minutes.
Wash, clean and halve the strawberries. Bake the tart in a preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer) for approx. 20 minutes.
Coarsely grate the chocolate. Mix with 125 g nuts and baking powder. Separate 3 eggs. Beat 3 egg whites and 1 pinch of salt until stiff. Mix 50 g butter and sugar until creamy. Stir in 3 egg yolks separately. Stir in rum and nut-chocolate mixture.
Fold in the beaten egg white.
Remove the tart from the oven and sprinkle with 2 tbsp. nuts. Spread strawberries on top and spread with the nut-chocolate mixture. Continue baking at the same temperature for about 25 minutes. Leave to cool in the mould.
Dust the strawberry tart with some icing sugar.