In a large bowl, mix the digestive biscuits, coconut and drinking chocolate. Add the butter and condensed milk and mix thoroughly until combined.
Take a small amounts of the mixture and roll into balls, before rolling in some desiccated coconut or chocolate sprinkles. Place the coated truffles into petit-four cases if desired.
Melt a small amount of white chocolate over a bain-marie or in short bursts in a microwave. Spoon a little onto the chocolate sprinkle covered truffles before topping with a holly leaf decoration. For the coconut covered truffle, use a spot of melted chocolate to stick the holly leaf decorations to the tops.