Beat the butter and sugar together until light and fluffy. I use a stand mixer but you could use an electric hand whisk.
Add in the plain flour, cornflour, salt and milk and mix until a dough is formed. You may have to take it out of the mixer and combine it slightly with your hands!
Refrigerate the dough for 1 hour.
Roll out the dough to about a 1/2cm in thickness and then cut out your ghost shapes.
Transfer your ghost biscuits onto a lined baking tray and chill again for 10 minutes. This will help the cookies keep their shape while baking.
Once the dough has chilled, preheat your oven at 160c/Gas mark 4.
Bake the biscuits in the oven for 10-12 minutes.
Once baked, allow to chill completely before adding decoration and filling.
Take half of your biscuits and decorate them as ghosts using white chocolate and milk chocolate. Allow the decoration to set in the fridge.
Once set, on the undecorated biscuits add 1 tsp of hazelnut filling and add the decorated biscuit on top to create your sandwich cookies!
Finally Eat!
