Soak the raisins in the rum for about 4 hours, covered.
Heat the rum-soaked raisins and liquid in a medium pan just enough to cook out some of the alcohol but not enough to dry out the raisins. Allow it to cool completely. (If there is too much alcohol the ice cream won’t harden quite as much but you could skip this step.)
In a medium sauce pan, combine the cream, milk, maple syrup and vanilla and bring to barely a simmer.
In a separate bowl, whisk the egg yolks until frothy.
Pour about a fourth of the hot cream mixture into the egg yolks, whisking constantly. Pour the combined egg yolk/cream mixture back into the saucepan with the rest of the cream mixture.
Bring the sauce to a simmer and cook, while whisking, until somewhat thickened – about 5 minutes.
Transfer the custard to a bowl and refrigerate until cooled. Alternatively, you can use an ice bath to cool the custard off even faster. (You can see the ice bath in the background – bowl inside a larger bowl filled with ice.)
Pour the cooled custard into the bowl of an electric ice cream maker.pouring primal rum raisin ice cream
Sample the custard. (This is a mandatory step.)
Add the rum raisins a few minutes before the end of the freezing process.
The ice cream will be ready to eat immediately but if you want a harder ice cream you can transfer to the freezer for a couple of hours before serving.