In a bowl, fully cover the cashews in water and soak overnight in the fridge.
Line the bottom and all sides of a 9 × 9-inch baking pan with parchment
paper (or use a springform pan).
To make the crust: In a food processor, pulse together the almonds, oats,
dates, blueberries, cinnamon, and cardamom until well incorporated. The mixture
should be thick and stick together when pressed.
Evenly press the crust over the bottom of the lined pan. Freeze for 20 minutes.
To make the batter: Drain the cashews and transfer to a large high- powered
blender (see Tip). Add the coconut milk, maple syrup, coconut oil, lemon
juice, orange zest, vanilla, and salt and blend until smooth and creamy.
If you want your cheesecake squares to have swirls, set aside most of the
cheesecake batter in a large bowl, leaving 1 /4 cup in the blender. Add the butterfly
pea flower powder, pitaya powder, or beet powder in the blender and
blend until smooth. Transfer the colored batter to a small bowl.
Remove the prepared crust from the freezer and pour the cheesecake batter
over the crust, spreading it evenly. To add swirls, drop small dollops of the colored
batter across the top of the cheesecake and swirl them with a toothpick
or chopstick.
Freeze the cheesecake for at least 6 hours and up to overnight.
Let sit at room temperature for 20 minutes before serving.