Quick soak the cashews by placing them in a bowl and covering with boiling water. Let stand for 30 minutes. While they are soaking, line a 20cm removable base cake tin with baking paper.
To make the base: place almonds, pecans and walnuts in a food processor and process until fine. Remove and set aside.
Add pitted dates to processor and process until smooth. Combine dates and nuts together and blend for 1 minute. Press the mixture into the cake tin base and flatten. Set in freezer while you make filling.
To make the filling, drain cashews and place the cashews, coconut cream, coconut oil, pulp from the 2 passionfruit, lemon juice and maple syrup in a blender and blend all the ingredients until very smooth and creamy. This will take between 5-8 minutes.
Remove cake tin from freezer and pour filling over. Smooth the top and place it back it the freezer to set for at least 3½-4 hours.
While the cake is freezing, make the topping. Place the passionfruit pulp and maple syrup in a small saucepan on medium heat and bring to simmer. Mix cornfour and water to make a runny paste. Gradually add this paste to the passionfruit while stirring. Simmer for 5 minutes until the mixture thickens. Add lemon juice and stir. Allow to cool.
When cheesecake is set and ready to serve, remove from cake tin and place on a serving platter. Garnish with fresh mint, if desired.
