1. Soak the cashews overnight (at least 12 hours) in enough cold water to cover them, at room temperature.
2. To make the base, put the digestive biscuits in a zip-lock bag and crush with a rolling pin until it resembles a fine crumb.
3. In a bowl mix together the crushed biscuits and melted butter.
4. Spoon the mixture into the bottom of the cheesecake pan/s and press it down firmly and evenly with the back of a spoon.
5. Place in the fridge to harden while you make the cheesecake.
6. Drain off and discard the water from the cashews and then place them in a food processor with the remainder of the ingredients.
7. Blend until the mixture is smooth and creamy.
8. Spoon the cheesecake mixture on top of the base/s, pressing down a bit to remove any air bubbles.
9. Place in the freezer for two hours to set before serving.
10. Garnish with finger lime pearls and/or lime zest.
11. Keep refrigerated