Place the raisins in a small bowl and pour the Caribbean rum over them. Cover the bowl and let the raisins soak for at least 2 hours (overnight for deeper flavor).

In a medium saucepan, combine heavy cream, whole milk, sugar, and kosher salt. Heat over medium, stirring occasionally, until warm and sugar dissolves.

In a separate bowl, whisk egg yolks until smooth and pale. Slowly pour about 1 cup of the warm cream mixture into the egg yolks while whisking constantly.

Gradually add the tempered egg mixture back into the saucepan with the remaining cream mixture. Stir constantly over medium-low heat until the custard thickens and coats the back of a spoon (about 5-7 minutes).

Remove custard from heat and stir in remaining Caribbean rum and ground nutmeg. Let it cool to room temperature before refrigerating for at least 4 hours or until completely chilled.

Churn the chilled custard in the ice cream maker according to manufacturer’s instructions. In the last 5 minutes of churning, add the rum-soaked raisins.

Transfer the ice cream to an airtight container and freeze for at least 4 hours or until firm. Scoop into bowls and enjoy.