Make sure that the bowl of your ice cream maker has been in the freezer for long enough, mine takes 11 hours to fully freeze.
Heat the raisins and rum in a small pan until simmering then cover and leave to soak overnight.
175 g (1 cup + 3 Tablespoons) raisins, 150 ml (½ cup + 2 Tablespoons) dark or spiced rum
Place the cashews in a heatproof bowl, generously cover with boiling water and leave to soak for 30-60 minutes.
160 g (1 + ⅓ cups) unroasted cashews
Place the porridge oats in a saucepan with half of the milk and bring to a gentle simmer, cook for about 5 minutes, stirring often to prevent the bottom from catching, until the oats are soft.
25 g (¼ cup) porridge oats, 800 ml (3 ⅓ cups) unsweetened non-dairy milk (preferably soya or oat barista)
Drain the soaked cashews really well then place them in a blender with the other half of the milk and blitz until smooth.
Add the cooked oat mixture to the blender along with the sugar, vanilla, melted coconut oil/butter and salt and blend until the mixture is very smooth with no hint of graininess. Stop and scrape down the sides as needed.
55 g (4 Tablespoons) melted refined coconut oil or vegan block butter, 160 g (¾ cup) caster, granulated or light brown soft sugar, 1 Tablespoon vanilla bean paste, ¼ teaspoon salt
Pour the mixture through a fine mesh sieve into a bowl, cover and refrigerate until completely cold; I leave mine in there overnight but it will take at least four hours.
The following day, place a fine mesh sieve over a jug. Tip the raisins and rum into the sieve and let drain thoroughly.
Whisk 60 ml (¼ cup) of the reserved raisin rum into the chilled ice cream base.
Churn the ice cream in your ice cream maker until it reaches soft-serve consistency then add the drained raisins. Due to the alcohol content, the ice cream may not freeze as firm as other recipes.
Once the ice cream is done churning, transfer it to a freezer-proof container and freeze for at least 4 hours, until firm, before serving.