Put the chocolate chip cookie crumbs in a bowl, add the cinnamon and melted butter, mix well and tip into a 22cm push-up-bottom or springform tin. Spread the mixture out evenly. Chill in the fridge until hard and set.
Melt the dark chocolate in a bain-marie (in a heatproof bowl over a pan of simmering water). Stir in the Kahlua or Tia Maria.
Grate the white chocolate. Cut the va