Place nuts in food processor and blend on high until the nuts are finely ground. Add the cacao,salt, agave and coconut oil. Pulse to combine.
Add the dates one at a time through the feed tube of the food processor while it is running. What you should end up with is a mix that appears rather like cake crumbs, but that when pressed, will easily stick together (if the mixture does not hold together well, add more dates).
Press into an 8" x 8" pan Place in freezer or fridge until ready to serve (it is also easier to cut these when they are very cold). Store in an airtight container.