Combine the sweetened condensed milk with the heavy cream A and heat it up until hot.
Remove from heat and pour over the dark chocolate.
Mix until smooth. Use a blender for this step to better emulsify the mix.
Place in the frigde for 3-4 hours or until chilled.
Remove from the fridge and stir in the heavy cream B and rhum.
Pour into your ice cream machine and churn according to your manufacturer's user manual. Mine took 60 minutes of churning.
Scoop into a casserole and place in the freezer to store.
Notes
You can easily customize the recipe by adding a wide range of extras to it: caramelized bananas, walnuts, peanuts, chocolate drops, berries etc. Or you can serve it with your favorite sauce: chocolate, berries, caramel, vanilla and the list can go on!