Place the walnuts, dates and coca powder into the food processor and process on the S blade until a sticky dough has formed. It should hold together when you break off a piece and squeeze it together.
Press this down into an 8x8 inch square dish and place into the freezer to set.
Add the soaked cashews, coconut, melted coconut oil, salt, syrup, peppermint extract and spinach into the blender and blend until smooth.
If you don't have a powerful blender, then you can do this step in the food processor as well.
Pour this out over the base and smooth down with a spatula or the back of a spoon. Return to the freezer to firm up before you add the topping.
Add the melted coconut oil, syrup and cocoa powder to the food processor and process into a smooth chocolate.
Pour this out over the mint filling and smooth down with a spatula or the back of a spoon.
Return to the freezer to set.
When it's very firm, slice into squares, decorate with some dessicated coconut and enjoy!