For the base, mix flour and 1 tablespoon sugar in a mixing bowl. Add 150 g butter in flakes and stir with a mixer until small crumbs are formed. Add the ice-cold water and continue stirring until the dough sets.
Knead briefly with your hands, wrap in foil and leave in the refrigerator for at least 1 hour.
Roll out the dough about 3 mm thick and line the tartlet cups (about 8 cm Ø) with it. Prick the base several times with a fork. Bake in the middle of the oven (electric oven: 180 °C) for 15-20 minutes until golden brown.
Take out and let it cool down.
For the pistachio brittle, chop the pistachios and roast them slowly in a pan. Then sprinkle 1-2 tablespoons of sugar over it, let it caramelize briefly.
For the filling, chop the chocolate and pour into a bowl. Bring the cream to the boil and pour over the chocolate, dissolve it in it while stirring. Stir in 60 g butter. Sprinkle the cooled cake base with approx. 2⁄3 pistachio brittle.
Then pour the chocolate mixture on top. Leave to rest in a cool place for 3-4 hours. Sprinkle with the rest of the brittle just before serving or shipping. YAMM!.