Shortbread tart shell
To make the shortbread, place the flour and cocoa in a mound on your work surface and make a well in the middle.
Place the butter in the well and use your fingertips to rub the butter into the flour.
Once the butter, flour and cocoa are mixed well, add the sugar and egg yolk and mix together by pushing the dough on the bench with the open palm of your hand until the pastry is homogeneous.
Shape into a disc, cover in plastic wrap and refrigerate for 2 hours or until firm.
Once the shortbread has hardened, break it up and mix it up by hand on your work surface until homogeneous.
Using a rolling pin, roll out the dough on a lightly floured surface to about 3 mm thick. You will need to move the dough constantly to stop it from sticking.
Use a fork to punch a few holes into the dough -this will allow for any air trapped at the base of your tart to escape without bubbling up the base of your tart.
Line the base and sides of a 22 cm tart ring or tart tin with removable base with the pastry, trim the excess with a knife, then place in the freezer for 30 minutes.
Preheat the oven to 180 degrees C.
Line the tart shell with foil or baking paper, then fill with uncooked rice. Bake the tart shell for 10 minutes, then remove the rice and foil and bake for another 10 minutes until the pastry is dry. Allow to cool before removing from the ring.
To make the salted caramel ganache, place the sugar in a heavy-based saucepan and stir continuously over medium heat until the sugar melts and turns into a blonde caramel.
Reduce the heat to low and continue stirring until the caramel begins to foam.
Add all the cream at once, keeping your hand well away from the pan as it will bubble up and create a lot of steam.
Remove from the heat and stand for 15 minutes or until slightly cooled. Place the chocolate and vanilla bean seeds in heat-proof bowl, then pour over the hot caramel and stir gently until combined.
Using hand held electric beaters, beat the mixture until thick and emulsified. You will notice that the ganache will go from a split, oily texture to a beautiful creamy viscosity.
Fold the salt in and the ganache is ready to use
Pour the ganache into the tart shell, allow to cool for 15 minutes or until the ganache thickens.
Decorate the top with raspberries, sprinkle with pistachios, then refrigerate until ready to serve.
Remove the tart from the refrigerator 15 minutes before serving. Serve with creme fraiche or ice-cream.