1 - Heat the rum in a small saucepan over medium heat until warm (do not boil).

2 - Remove from heat and stir in the raisins and vanilla extract.

3 - Let the mixture sit for at least 30 minutes.

4 - After soaking, drain off the extra rum, but keep ¼ cup of the rum and reserve it to mix into your ice cream base.

5 - In a large bowl, whisk together the sweetened condensed milk, dark brown sugar, cinnamon, allspice, salt, and reserved rum (¼ cup).