300g/10½oz fresh raspberries
275²µ/9½´Ç³ú caster sugar
2 tsp cornflour
150g/5oz blanched shelled hazelnuts
1 tbsp icing sugar, sifted, plus extra to serve
½ tsp vanilla extract
100g/3½oz plain chocolate (minimum 70% cocoa solids), broken into pieces
450ml/16fl oz double cream
5 large free-range egg whites