Ingredients:
568ml carton double cream
300ml whole milk
½ vanilla pod, split
6 large egg yolks
50g caster sugar
300g raspberries
Icing sugar to taste
Put the cream, milk and vanilla pod in a heavy-based pan and heat until just below boiling point. Meanwhile, beat the egg yolks and sugar together in a bowl until thick and creamy. Remove the vanilla pod from the hot cream mixture. Pour the cream mixture on to the egg yolk mixture, whisking constantly. Return the mixture to the pan and heat very gently, stirring, until the custard thickens enough to lightly coat the back of a wooden spoon – this should take 10-12 minutes. Strain the custard into a clean bowl and leave to cool. At this stage, you can chill the custard for a few hours before continuing.
You can now process the custard in an ice cream maker until thick and holding its shape. Transfer to a freezer container. Alternatively, pour the custard into a freezer container, cover and place in the freezer. Remove after 2 hours and whisk well to break up the ice crystals. Return to the freezer. Repeat the process twice more or until the ice cream is extremely thick and holds its shape.
Meanwhile, purée the raspberries in a blender. Sieve to remove the pips. If the purée tastes tart, sweeten with a little icing sugar (it will taste even less sweet when frozen).
Spoon the raspberry purée through the thick ice cream, making a ‘ripple’ effect. Cover and freeze overnight or until firm. Remove the ice cream from the freezer 5 minutes before serving. Scoop into balls and serve.