Start by lining a 9x9 inch baking dish with parchment paper, allowing some overhang on the sides for easy removal later.
In a food processor, add the roasted cashews and pulse until finely ground but not turned into nut butter, creating a crumbly texture.
Add the pitted medjool dates, coconut oil, coconut or almond milk, vanilla extract, and salt to the food processor. Blend until smooth and creamy, scraping down the sides as needed.
In a large mixing bowl, combine the old-fashioned oats, cooked quinoa, and ground walnuts or almonds. Pour the date mixture over the dry ingredients and mix until evenly coated.
Gently fold in the chopped dark chocolate chunks, careful not to over-mix to keep chocolate pieces intact.
Transfer the mixture to the prepared baking dish and firmly press down into an even layer using a spatula or hands.
Place the baking dish in the refrigerator for at least 2 hours, or until firm enough to cut into bars.
Once set, lift the bars out using the parchment paper and cut into squares or rectangles. Sprinkle sea salt on top before serving.