Preheat the oven to 190 °C.
Put all the ingredients for the base in a food processor and mix until sandy. Press into a cake pan and bake for 12 minutes in the oven at 190 °C. Remove the pan and let it cool.
Put the cream, the seeds from the vanilla pod, and the pod itself in a saucepan and bring to a brief boil.
Remove the vanilla pod. Add the butter and chocolate and let it rest for 5 minutes. Then mix everything together and keep stirring until it becomes a nice shiny, homogeneous mass.
Pour the chocolate mixture into the cooled cake base and let everything set in a cool place like the garage. (In the fridge, it will become too hard, so it's best to find a cool spot.)
Sprinkle salt flakes on top and cut into bars or pieces.
Tips
You can also make the bottom very well with other nuts or seeds. Experiment to your own taste!