Activate the Cocoa: In the medium mixing bowl, whisk the Dutch-processed cocoa powder with 2 tablespoons of the cashew milk until a smooth, thick paste forms. This step ensures a deep, lump-free chocolate flavor throughout.
Combine Dry Staples: Add the rolled oats, protein powder, ground cinnamon, and fine sea salt to the bowl with the cocoa paste. Stir briefly to distribute the ingredients.
Introduce Liquids: Pour the remaining cashew milk, date syrup, and vanilla extract into the bowl over the dry ingredients.
Create the Base: Whisk everything together vigorously for about 1 minute. Ensure all ingredients are fully incorporated and the mixture is smooth and consistent, with no visible clumps of powder.
Portion and Chill: Carefully divide the oat mixture evenly among the four airtight jars. Seal them tightly and place them in the refrigerator to set for a minimum of 3 hours, or preferably up to 8 hours for the thickest consistency.
Final Stir and Serve: Before serving, remove the jars from the refrigerator and give the oats a thorough stir to create a creamy, uniform texture. The oats will have thickened considerably into a pudding-like state. Enjoy chilled, directly from the jar.