Pre-heat the oven to 120° C.
Whisk together the egg whites with a pinch of salt until soft peaks form. Add 50g of the caster sugar, and whisk until you have a thick, glossy meringue. Spoon onto a lined and oiled baking tray.
Transfer to the oven and lower the temperature to 100° C.
Bake in the oven for 60 minutes until dried and baked. Remove and reserve to one side.
Line the base and sides of a 6 inch cake tin with parchment.
In a mixing bowl, mash together the raspberries with half of the remaining caster sugar. Whip together the double cream with the rest of the caster sugar until you have soft peaks.
Beat the crème fraiche in a separate bowl so that it resembles soft peaks. Fold the cream and crème fraiche together gently. Add the mashed raspberries to the cream and crème fraiche mixture and stir a few times until you have a swirled mixture.
Crush the meringue and fold gently into the mixture. Spoon into the cake tin and smooth the top. Transfer to the freezer and let it firm up uncovered. Once firm, wrap with clingfilm and freeze overnight.
Before serving, remove from the freezer and allow to sit for 5 minutes. Turn out, cut into wedges using a hot knife and serve with the reserved raspberries.
*This pudding is very rich and indulgent so shouldn't be eaten too often. But it's perfect for those special occasions!