Place dates in a bowl and cover with 1 cup very hot water (almost boiling); leave to soak for 15 minutes.
Blend nuts in a food processor until they resemble fine breadcrumbs, then pour into a mixing bowl.
Drain dates thoroughly, checking there are no pips and reserving the soaking water. Place dates in the food processor, along with cocoa powder, orange juice and zest, then blend.
Slowly add the ground nuts while the food processor is running, until you have added them all. If the mixture is too dry, add a little of the reserved date soaking water. If it is too wet, add a little desiccated coconut until the mixture becomes firm enough to roll into balls that hold their shape.
Roll heaped teaspoons of the mixture into balls, then roll in coconut to coat. Place the balls on greaseproof paper and chill in the refrigerator until ready to eat (1-2 hours).