Break the dark chocolate up in to a measuring jug and place in a pan filled with simmering water.
When the chocolate has melted remove the measuring jug from the pan.
Mix in the double cream and liqueur. You can use any liqueur you like.
Return to the pan of simmering water and leave for a minute. Mix until the mixture becomes smooth.
Put the measuring jug in a fridge and leave to set for about 5 hours.
When the mixture is firm remove it from the fridge. Take a spoonful of mixture and roll in to a small ball. Roll all the mixture in to balls and place them in to a bowl. Prepare a tray or board by wrapping it in tin foil.
Melt down the white or milk chocolate like you did with the dark.
Dip the dark chocolate balls in to the white/milk chocolate and place on the tray.
Alternate between white and milk chocolate to coat your balls. Sprinkle with coffee, chopped nuts or anything else that may taste nice.