Melt the chocolate in a microwave or over a pan of simmering water until smooth.
Crush the biscuits in a freezer bag with a rolling pin into rubble.
Cream the butter and caster sugar in a large bowl until soft and light.
Beat the eggs into the butter mixture one by one, then stir in the amaretto.
Sift cocoa powder into the cooled chocolate and stir to combine.
Mix the chocolate into the egg mixture until smooth.
Fold in the chopped nuts and crushed biscuits until completely coated.
Refrigerate the mixture for 20 to 30 minutes to firm up slightly.
Shape the mixture into a 30cm log on a surface covered with cling film.
Wrap the log tightly in cling film and twist the ends to create a smooth cylinder.
Chill the log in the fridge for at least six hours or overnight.
Remove cling film and rub the log with icing sugar.
Tie string around the log in loops to create a traditional salame pattern.
Serve cold by cutting into thin slices.