Crush up your graham crackers or digestives biscuits in a food processor, or in a bag with a rolling pin.
Pour the cookie crumbs into a large bowl and add the salt and desiccated coconut.
In a large, microwavable jug or bowl, mix together the condensed milk, butter, and cocoa powder. Microwave at 30-second intervals, stirring in between, until everything is melted and combined.
Pour the melted ingredients into the crumb/coconut mixture and mix until completely combined.
Chill for 20 minutes to make the mixture easier to roll.
Take 1 teaspoon of the mixture and roll it with your hands to form a ball. Put the ball in a bowl of powdered sugar and roll around to coat. Repeat until all the mixture is gone.
Notes
You can also roll the chocolate truffles in chocolate sprinkles if you prefer that to powdered sugar!