Hazelnut Rum Tart

First, make the tart crust.
Put the cake flour in a bowl, and add the butter, which should be cut into 1 cm cubes.
Use something like a dough cutter to mix the two together while chopping up the butter finely.
Make a depression in the center and add the sugar, salt and egg white.
Use a spatula or your hands to mix it all together and gather the dough into a ball.
Wrap the dough in plastic wrap, and let it rest in the fridge for at least 30 minutes.
Now, make the filling.
Let the butter and egg warm to room temperature.
Bake the hazelnuts in a preheated 160C oven for 10 minutes, then peel them.
Powder 40 g of the hazelnuts in a food processor or mill, and chop the rest of the nuts in half.
Put the butter and sugar in a bowl and mix well.
Add the egg, rum, powdered hazelnuts and chocolate chips in that order, mixing each ingredient in well as they are added.
Preheat the oven to 180C.
Flatten the dough from Step 3 to a 4-5 mm thickness, then line the tart pan with it.
Cut off any excess dough.
Pour the filling from Step 7 into the crust and gently level the surface.
Evenly space the halved hazelnuts on the surface of the tart and bake it for about 35 minutes at 180C.
It's finished baking.
Once it has cooled, remove the tart from the pan.
Slice the tart and serve it up on plates.