Add cashews to a bowl and cover with warm water, let soak for at least 30 minutes. When you are ready to make the truffles, add the ground flax seeds to a small bowl with the warm water and let sit 3 minutes. Drain and rinse cashews, then add to a food processor with the flax mixture and all remaining ingredients. Pulse until a smooth batter forms. Roll batter into balls and then roll balls in cacao powder. Place in a container and cover, let set in the refrigerator for one hour.