Line a square pan with parchment paper and set aside.
In a high-speed blender or food processor, add your almonds and walnuts and blend until crumbly- Do not over blend or else you will be left with almond butter.
Add your dates and blend well, until combined. Regularly scrape down the sides. Add your cocoa powder and continue to blend. If the batter is too crumbly, add 2 tablespoons of water, until smooth and glossy.
Transfer to the lined pan and press firmly into place. Refrigerate until firm.