I love all ice-cream (except ‘mackerel dog-biscuit crunch’). Ripples give that added pleasure every time you hit a rich seam. Then the ripple runs out and you have to mine deeper, and then it’s just…finished.
To make the ice-cream, pour the cream and milk into a large saucepan. Cut the vanilla pod in half lengthways and scrape out the seeds with the point of a knife. Whisk the seeds into the pan and add the pod. Bring to the boil, then immediately turn off the heat. Remove the vanilla pod and wash well. Allow it to dry and keep it, as it can be used to flavour sugar and subsequently future ice-creams and puddings.
Whisk together the egg yolks and caster sugar until pale. Pour in the milk and cream mixture, whisking immediately. When thoroughly combined, return the liquid to the saucepan and set over a low heat.
Cook for 15–20 minutes, stirring constantly, until the custard is thick enough to coat the back of the spoon. This custard stage needs your total commitment; you must robotically stir at all times. Do not allow it to overheat or the egg yolks will begin to scramble. (This can possibly be salvaged by pouring the mix through a fine sieve; if after sieving it is still grainy, you will have to start again.) Remove the pan from the heat and pour the custard into a clean bowl. Cover the surface with clingfilm to stop a skin from forming. Leave to cool for 30 minutes.
While the custard is cooling, make the raspberry ripple sauce. Rinse the fruit and put it into a large saucepan with the sugar and water. Bring to the boil, then simmer rapidly for about 10 minutes until the fruit has totally collapsed. Put a sieve over another small saucepan and tip in the contents, gently pressing while stirring. Return to the heat and simmer gently until reduced. It wants to be the consistency of cough mixture. Do not allow it to overcook or it will become too jammy, or undercook, as when frozen it will add a water-crystal element to an otherwise creamy luxury. Leave to cool.
Pour the cooled custard into an ice-cream machine and churn for about 40 minutes until it is very thick and smooth. Spoon roughly a third of the ice-cream into a lidded freezer-proof container.
Top with generous spoonfuls of the raspberry sauce, then add more ice-cream. Continue in loose layers until all the ice-cream and sauce are used up. Take a table knife and swirl it very lightly through the ice-cream to roughly marble the sauce through the mixture. Cover with the lid and freeze until solid.
Remove from the freezer and leave to stand at room temperature 10 minutes before serving. Eat in the sun in joyful ignorance that you are dripping it all over your T-shirt.