For the base blend the hazelnuts in a good processor for a minute or so, then add the reminding ingredients until it comes together. Press into a small (10cm) cake tin. Refrigerate while you make the next layer.
For the Goji Papaya layer blend all the ingredients in a blender or Nutri bullet until well combined. Then spoon this mixture onto the base later and refrigerate.
For the chocolate layer blend the ingredients in a NutriBullet or blender until smooth. Spread this final layer on top of the cake. Keep in the fridge or freezer until firm.
I added a dark chocolate layer on top - melted 100g of dark chocolate with a tablespoon of coconut oil. I drizzled this on top of the cake. If the cake has been in the freezer it will help the chocolate drizzle to set.