Soak the raw cashews that you will later be using in the mango layer in 3 cups of water, with 3 tablespoons of lemon juice or apple cider vinegar and a pinch of Himalayan salt added, overnight or for at least 6-8 hours.
Line a 22cm springform cake tin with baking paper.
To make the base add the macadamias, activated buckwheat and coconut flakes to a food processor or high powered blender and pulse until it has the consistency of wet sand.
Add the rest of the base ingredients and process until completely combined.
Press the mixture into the cake tin, pressing it evenly with the palms of your hands. Place the tin into the freezer while making the mango filling.
Drain the soaking cashews and rinse them well.
Make the mango layer by blending the cashews with the coconut cream, coconut butter, maple syrup, mango and lime juice until very smooth and creamy, scraping down the sides of the food processor or blender occasionally. Be patient this will take a few minutes.
Pour the mango filling over the base, smooth the top evenly and place the cake tin back into the freezer to set overnight or for at least 6 hours.
To toast the coconut flakes for topping the cake spread them over a baking tray and put into a 120C oven for 15 minutes, or until lightly golden. Let them cool completely.
Take the cake out of the freezer to soften a little 1 hour before serving.
Decorate the cake with the passionfruit and toasted coconut flakes.