Put the chocolate and butter into a heatproof bowl set over a pot of simmering water and melt them both, slowly.
When the mixture is smooth, take the bowl off the heat and whisk in the double cream and Baileys.
Put a plastic wrap over the bowl and put it in the fridge, leave there for 2 hours or longer.
Melt your chocolate for the dip the same way you melted the mixture for the truffles in a double boiler.
When ready, use a round spoon or a melon baller to scoop out the truffles. Don't worry if they are not perfectly round like store bought. The real truffles aren't!
Dip each truffle into the melted chocolate and take it out with a fork so the excess chocolate will drip off and put on parchment paper, sprinkle with coloured sugar or anything else you like to decorate. You can also drizzle contrasting colour of chocolate.
Leave truffles in a cold place to set.