Place raisins and rum in a pan and bring to the boil then allow to cool.
Whisk egg yolks and sugar in a small bowl until pale in colour, set aside.
Add cream and milk to large saucepan and heat on high until simmering. Remove from heat and slowly add 1 cup of heated milk to the egg yolks, all the while whisking the yolks.
Slowly pour yolk mixture, golden syrup, and vanilla into a saucepan of milk and continue heating on medium heat until ice cream base thickens. You'll know the base is ready when it coats the back of a spoon.
Stir in raisins and rum until combined.
Allow ice cream base to cool in the fridge overnight or for at least 3 hours.
Add base to ice cream maker and churn. Once complete, add to a container and freeze for an additional 2-3 hours until hardened.