Preheat oven to 180°C and line the base of the tin(s) you will use to bake these. If you are making shortbread rather than a base for a cheesecake, simply line a baking sheet.
Place sugar and salt into the Thermomix bowl and mill 5 sec/speed 10.
Add butter, flour, cocoa and vanilla and blend 15 sec/speed 6.
Add cocoa nibs and mix 5 sec/speed 5.
Tip out onto floured mat and bring together with your hands. Roll and cut into shapes or line your baking tins accordingly.
Bake around 10-15 minutes until fragrant.
Use as a cheesecake base.
Cut into shapes and bake as biscuits or cookies. Drizzle with melted chocolate and top with chopped toasted nuts.