Soak cashews in very hot water for 30 minutes. If using a Medjool date as a sweetener, soak in hot water for 10 minutes.
Drain and rinse cashews. Drain chopped date.
Place cashews, date (or maple syrup), oats, coconut flakes, water, and sea salt in a high-speed blender and blend for about 60 seconds, or until smooth.
Pour mixture through a nut milk bag (or a clean thin towel) over a large mixing bowl. Strain and squeeze really well until only the pulp is left. You might want to double strain the mixture to make sure all sediment is removed. Be patient - this process will take a few minutes.
And enjoy! You can store in a mason jar in the fridge for up to 4-5 days.