Ideally soak the cashew nuts overnight. If you don't have time just fill and boil the kettle and soak in boiling water for 30 mins. Drain and rinse them.
Melt the 150g of chocolate and the 100g of coconut oil until its runny. In a food processor add all the ingredients for the ganache and blend on high speed for 5 mins until the texture is wonderfully smooth and delicious.
Line an 8 inch springform tin with baking parchment. Scoop and spread this ganache filling in the pre lined tin and spread out evenly. Put in the fridge to set for 3 hours.
Remove from the fridge and using a pallet knife or butter knife carefully cut around the cake form the springform tin. Remove the sides of the springform tin.
Chop the 150g of dark chocolate for the topping into small even pieces.
Boil the kettle and fill a small pot ⅓ full with boiling water and put on medium heat. Put 100g of the chopped dark choc and 1 tbsp of coconut oil into a bowl that allows heat to transfer such as a metal or glass bowl and allow to melt. Once the content is all melted remove from the heat and add in the remaining 50g of chopped chocolate slowly at a time and mix until it is all melted. This method will ensure that your melted chocolate is thick enough that when added to the firm ganache cake that it will weep down the sides giving you a beautiful look. The addition of the coconut oil means that when you go to cut the chocolate it is easy to slice through and won't snap.
Pour the melted chocolate slowly and gently on top of the ganache cake and gentle spread around ensuring that some part dip over the edge to give the appearance of chocolate weeping down the sides.
Decorate with anything you like on top such as chopped pistachio, raspberry, rose petals etc etc
Best served in small slices as its so rich and kept in the fridge so it holds its form. Enjoy!