Line base of cake tin with baking paper.
Blend base ingredients and place in cake tin, press down with fingers until even and place in freezer.
Blend cashews, coconut oil, vanilla extract, coconut water and sweetener and blend until smooth.
Pour in some of the filling in the cake tin and leave the rest for the green tea layer.
With remaining cashew filling, add in spinach, mint, peppermint extract and matcha powder, blend until combined and pour into the cake tin.
Place in freezer and let it set for about 4 hours.
Break up chocolate bar in a heat proof bowl, boil water in a saucepan and place bowl in water. Let the chocolate melt, and grab the bowl with a tea towel so you don't burn your hand and pour onto the cake. Add a sprinkle of matcha powder, mint and pistachio nuts.
Store in fridge or freezer!