Add the cashews to a bowl and cover with boiling water. They need to soak for around 30 minutes to help them blend.
Blend the digestive biscuits with the coconut oil and cinnamon until they have a fine crumb.
Line a 20 cm (8inch) springform pan with parchment paper and then add the crumb base. Push the mixture down until evenly firmed. Put the tin in the freezer whilst you make the filling.
Put all of the remaining ingredients into a blender and mix until super smooth - this took about 3 minutes in my blender.
Remove the cake tin from the freezer and add the filling. Tap the cake tin to remove air bubbles. Loosely cover with tin foil.
Place the trivet in the instant pot and add 300ml (1.5 cups) of cold water.
Make a sling using tin foil and use it to lower the cake tin into the instant pot.
Put the lid on and set to high pressure for 30 minutes. Allow to naturally release (around 20 minutes).
Remove the cake tin from the instant pot and place on a cooling rack. Remove the foil.
Leave on the cooling rack for around an hour and then place in the fridge for a further 24 hours whilst the cheesecake develops its flavour.
Serve and enjoy!