Put the raspberries and blackberries in a small pan with 2 tbsp water and 40g caster sugar. Heat gently, crushing the berries slightly with the back of a spoon, until the sugar has dissolved and the juices start to run. Cool then chill. Put a 1½-litre plastic container, with a lid, in the freezer to chill.
Put a bowl over a pan of simmering water and whisk the egg yolks and remaining caster sugar together for about 5 minutes, until thick and pale. Remove from the heat and whisk in the crème fraîche.
Scrape the seeds out of the vanilla pod, add to the double cream and whisk until just holding its shape. Fold into the crème fraîche mixture and pour into the chilled container. Pour the berry mixture over and use a spoon to create ripples and marbles, do not overmix or you’ll lose the definition. Freeze for at least 6 hours. Transfer from the freezer to the fridge 20 minutes before scooping and serving.
To make the tuilles, heat the oven to 170c/fan 150c/gas 3. Whisk the icing sugar, flour, melted butter and egg whites together to form a paste. Line a baking sheet with non-stick baking parchment and spread the mixture out very thinly in 9cm circles. Sprinkle with almonds and bake for about 6-8 minutes, until golden brown. Cool on the baking sheet before carefully peeling off. Serve with the ice cream.