For the buttercream, stir the pudding powder, 75 g sugar and 50 ml milk until smooth. Bring 450 ml milk to the boil, stir in the pudding powder. Bring to the boil again while stirring and simmer over low heat for about 1 minute. Put the pudding in a bowl, place the foil on the surface and let it cool down at room temperature. Store 250 g butter also at room temperature. Beat 250 g sugar, vanilla sugar, salt and 250 g soft butter with the whisk of the hand mixer until very creamy. Stir in the eggs one after the other.
Mix flour, cornstarch and baking powder. Stir the rum into the dough by the spoonful. Pour the dough into a greased, flour-blended box form (26 cm long). Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 45-50 minutes. Leave to rest in the pan for 5 minutes, carefully turn out of the pan and let it cool down. Wash and clean 125 g strawberries and puree with 20 g sugar. Whip the butter, which has been stored at room temperature, until creamy white with the whisk of the hand mixer (approx. 15 minutes). Stir in the pudding by the spoonful. Gradually stir in the strawberry puree as well. Stir jam until smooth. Cut the cake twice horizontally. Spread some cream on the bottom cake layer. Spread the jam evenly on top and carefully spread some cream on top. Place the second cake base on top.
Stir in the pudding by the spoonful. Gradually stir in the strawberry puree as well. Stir jam until smooth. Cut the cake twice horizontally. Spread some cream on the bottom cake layer. Spread the jam evenly on top and carefully spread some cream on top. Place the second cake base on top. Spread with about 1/3 of the remaining cream. Place the third base on top. Spread with the remaining cream. Wash, clean and slice 100 g strawberries. Decorate the strawberry cake with them. Sprinkle with pistachios. Chill the cake for at least 2 hours before serving
Spread with about 1/3 of the remaining cream. Place the third base on top. Spread with the remaining cream. Wash, clean and slice 100 g strawberries. Decorate the strawberry cake with them. Sprinkle with pistachios. Chill the cake for at least 2 hours before serving