- Blitz all crust ingredients together in a food processor until dough-like consistency forms.
- Press crust mixture firmly into coconut oil-greased square cake tin (8x8) lined with cling film for easy removal.
- Place in freezer for half an hour or just whilst you make the filling.
- Blitz all filling ingredients together until a caramel consistency forms (use a spatula to push down the mixture into the food processor bowl and add more water if it's too thick and sticky).
- Spread filling evenly over the crust using a spatula.
- Add walnuts (or pecans) on top and push down slightly so they set in the caramel filling.
- Place back in freezer for at least half an hour (or until the filling is set).
- Store in an airtight container in fridge or freezer for up to 2 weeks. Best eaten straight from freezer in warmer weather.