In a medium bowl, melt the chocolate, butter and cream in the microwave or over simmering water. Stir until melted and smooth. Stir in the hazelnuts, Digestive biscuits and raisins. Chill in the fridge for about an hour, or until cool enough to shape but not yet firm.
Scrape the mixture out onto a piece of plastic wrap and shape into a log (or two, if you want to make smaller ones). Wrap in the plastic wrap and return to the fridge for several hours, until firm. Take it out and dust it generously all over with icing sugar (you can do this by dumping some icing sugar on the countertop and rolling the log around in it). When you’re ready to serve it, take it out of the fridge for half an hour or so to make it easier to slice.
Makes 1 large or two small salamis.