Roughly chop the raisins. Warm 1/2 cup of rum in a saucepan.

Add chopped raisins and stir for 3-5 minutes. Remove from heat and cool.

In a large bowl, combine sweetened condensed milk, 1/4 cup rum, and 1 teaspoon vanilla powder. Whisk until smooth.

Gently fold the cooled rum-soaked raisins into the ice cream base.

Whip cold heavy cream in a separate bowl until stiff peaks form.

Fold whipped cream into the raisin mixture in three additions.

Transfer the mixture into a freezer-safe container and freeze for at least 6 hours.

Remove from the freezer and let sit for 5-10 minutes before serving.