My flatmate makes these whenever there's a bakesale and they're really tasty and easy to do. I didn't have the recipe to hand, so a quick google led me to 16 digestive biscuits, a can of condensed milk and 6 heaped tablespoons of drinking chocolate. Very easy!
First of all, smash the digestives into crumbs. I put mine in a large bowl and bashed them with the end of a rolling pin.
After the digestives have been crushed, add six heaped tablespoons of drinking chocolate and mix together.
Then, add the whole can of condensed milk and mix thoroughly until you have a sticky mixture. Refridgerate for 10-20 minutes until the mixture keeps it shape when you mould them.
Pour some drinking chocolate in a bowl. Roll the mixture in between your hands until you have a ball shape and then roll in the drinking chocolate powder. Repeat!