Put the cashews in a large heatproof bowl and cover with boiling water from the kettle. Leave to soften for 1 hr.
Heat the oven to 200C/180C fan/gas 6. Line the base of a 20cm (4cm deep) round cake tin with baking parchment. To make the base, put the oats, sugar and a pinch of salt in a food processor and blitz to a fine powder. Pulse in the coconut oil until combined, then gradually pulse in 3-4 tbsp water until it comes together into a dough – it should be crumbly, not sticky.
Press the dough into the base and up the side of the tin using the back of a spoon. Bake for 20-25 mins until golden. Leave to cool.
Reduce the oven to 180C/160C fan/gas 4. Drain the cashews, then transfer to a blender along with the coconut cream, soft cheese, cornflour, vanilla, maple syrup, coconut oil, lemon juice and a pinch of salt. Blitz on high speed until the mixture is creamy and smooth.
Pour the cashew and soft cheese mixture over the base and bake for 1 hr-1 hr 15 mins until the edge is just coloured and the centre has mostly set with just a slight wobble. Leave to cool completely (it will sink slightly as it cools), then chill for at least 3 hrs, or overnight.
Put the raspberries and sugar in a heatproof bowl and microwave for 1 min 30 seconds on high. Stir and leave to cool completely, then pour this over the cheesecake. Scatter over the pistachios and candied clementine peel. Will keep chilled for up to three days.