Place the raisins and rum in small bowl. Let it sit for about 3 hours.
Combine the milk, cream and sugar in a medium sauce pan. Bring to a gentle boil over medium heat.
In a small mixing bowl whisk the egg yolks until smooth. Add about half of the hot liquid to the egg yolks and whisk until smooth.
Add the yolk mixture to the saucepan and whisk until incorporated. Bring the liquid back to simmer and continue to cook for about 5 minutes, stirring constantly.
Remove from the heat and pour the mixture into a glass bowl and place a piece of plastic wrap directly on top of the mixture. Cool the mixture completely.
Pour the mixture in a plastic container and put it in the freezer. After 45 minutes, take it out of the freezer. Add raisins and rum mixture to the custard and with an electric mixer, whisk for about 2 minutes and return to the freezer.
Continue doing the same process every 30 minutes, until the ice cream is frozen. This will take about 3 hours.
Note: If you have an ice cream maker: Transfer custard to the ice cream maker and follow manufacturer's instructions.