Line an 11x8x2 baking dish (or similar size) with nonstick parchment paper and freeze it for at least 8 hours and up to overnight. I use binder clips to hold down the sides.
Place cashews in a bowl in a shaded area on your counter. Cover with filtered, room temperature water and soak 8 hours or overnight.
Drain and rinse cashews. Combine all frozen yogurt ingredients in a blender and blend until smooth and creamy. Pour into cold baking dish and freeze 30 minutes, uncovered.
Use hand mixer to CAREFULLY beat mixture for 5 minutes. Freeze and repeat this process every 30 minutes, 6 more times (yes, over three hours!).
Cover thoroughly and freeze another 8 hours before enjoying. I suggest letting ice cream sit out for 15 minutes or so before scooping. Leftovers will keep tightly sealed in the freezer for 1 month.