Rinse box form (approx. 750 ml content, approx. 24 cm long) with water and line with cling film. Sort the raspberries. Separate the eggs. Beat the egg yolks with 75 g icing sugar and 2 tbsp. hot water in a large bowl over a hot water bath until thick and frothy. Remove bowl from water bath and place in a bowl filled with ice water. Whisk the mixture with a whisk until it has cooled down completely and has a creamy consistency
Stir the sour cream into the egg mixture. Whip cream and egg whites separately until stiff. Using a whisk, carefully fold the cream and beaten egg white into the cold egg mixture. Finally fold in approx. 200 g raspberries. Pour the mixture into the mould, smooth it down and freeze for at least 4 hours, preferably overnight. Roast the hazelnuts in a pan without fat until golden brown, take them out and let them cool down
Mash 125 g raspberries and 1 tablespoon icing sugar with a fork. Turn out the parfait from the mould, cut off 4 thick slices and cut them in half diagonally (immediately refreeze the rest of the parfait and use it for other purposes). Arrange the parfait with hazelnut leaves, the remaining raspberries and raspberry puree on plates and serve immediately
waiting time approx. 4 hours