Put a 30 cm loaf tin into the freezer. In a bowl, whisk the double cream until it starts to thick- en. In another bowl, beat the egg whites to stiff peaks, then slowly sift in the caster sugar. Fold in the double cream and set aside. Lightly oil a heatproof surface, or greaseproof paper on a heatproof surface, with a drizzle of olive oil. Heat the sugar in a pan until caramelized then add the hazelnuts. Pour over the marble surface or greaseproof paper. Set aside to harden. Using a rolling pin, lightly crush the hazelnuts to break up the caramel, then fold through the cream mixture. Spoon into the loaf tin and freeze for 6 hours. To make the coulis, blend together the raspber- ries and the sugar in a food processor, then strain through a fine sieve and refrigerate until you are ready to serve the semi-freddo.