Preheat the oven to 180'C.
Mix the flour, butter, salt and icing sugar together with your fingers until it becomes a crumble. Use your hands to gently make it into a dough. Roll into a cylinder using cling film and then place in the fridge for 15 minutes.
Once cool, cut the cylinder into discs around 5mm thick. Place on a baking sheet and bake for 12 to 15 minutes.
Once golden brown, use a pastry cutter to trim into perfect circles and dust with caster sugar whilst still warm.
Place the biscuits on a cooling rack to cool.
Split the vanilla pod and scrape out the seeds. Break the chocolate into pieces.
Place the milk, cream, sugar, spices and the vanilla pod and seeds in a saucepan and bring to the boil. Pass the liquid through a sieve and then pour over the chocolate. Mix gently to melt and incorporate the chocolate. Serve immediately.
«Run your pastry cutter under cold water every once in a while, this will make the biscuits easier to cut.»