Chop the Stracci and hazelnuts in a food processor, transfer them into a bowl with 2 tablespoons of cocoa powder and mix with a wooden spoon. Add the bittersweet Viallella fondente, the grated ginger and the chilli pepper, stirring continuously in order to mix all the ingredients together well (if you have dough mixer better still, “the work” will be easier). When the mixture is smooth and compact, using wet hands, shape it into small balls with a diameter of roughly 1.5 cm and place them on a tray covered with greaseproof paper. When you have finished making them all, put the tray in the fridge for 10 minutes. Melt the dark chocolate in a bain-marie. Take the truffles out of the fridge, dip them – one at a time – in the melted chocolate and put them back on the greaseproof paper. When they have cooled down completely, dust them with the remaining cocoa powder.