1. Preheat the oven to 180°C and place the hazelnuts or almonds on a baking tray. Grill for 10 minutes.

2. Put the hazelnuts or almonds into a blender and mix to a very fine powder.

3. Mix flour, hazelnuts/almonds, butter and sugar in a bowl and knead to a homogeneous dough.

4. Wrap the dough in foil and let it rest in the fridge for a few hours.

5. Take the dough out of the fridge and form it into a roll. Cut into 2 cm thick slices. Results in about 80 pieces for 40 biscuits.

6. Form the dough pieces into balls and place them on the baking tray covered with baking paper, pressing lightly on the balls to flatten the lower part slightly.

7. Bake the biscuits for 20 minutes, remove from the oven and allow to cool.

8. Cut the chocolate into small pieces and melt with a little butter in a water bath.

9. Coat the flat side of the cookies with chocolate and glue together with the flat side of another cookie.