Chocolate truffles

1. Put the chocolate in a medium bowl. In a small pan, gently heat the cream and butter until the cream is steaming; take off the heat before it boils. Use a rubber spatula to mix in the melted butter and cream, then pour the mixture over the chocolate. Leave for a minute to allow the chocolate to melt, then stir to combine. Stir in the liqueur, if using. Set aside to cool, then cover and chill for 2 hours (or 3 hours, if using the liqueur).

2. Put a teaspoon or melon baller in a mug of just-boiled water, then use it to scoop equal-sized balls of chilled ganache (about 2cm diameter). Briefly roll each ball between your palms to make a rough sphere and place on a board. Dust your hands with cocoa powder and roll each truffle again to even out the surface.

3. On 3 plates, spread out the remaining cocoa powder, the raspberries and nuts. Roll each truffle through one of the coatings until evenly covered. Chill on a clean plate for 1 hour, then transfer to a gift box. These will keep chilled in an airtight container for up to 1 week; serve at room temperature.