Begin by ensuring your sugar-free condensed milk is already prepared and completely cooled to room temperature. This foundational step is key for achieving the ultimate creamy texture.
In a spacious mixing bowl, combine the cooled sugar-free condensed milk with the heavy cream, powdered sweetener, the optional vodka (for extra smoothness), vanilla extract, and a touch of salt. Whisk everything together until the mixture is uniform and well blended.
Take a moment to taste your mixture and adjust the sweetness to your liking. If you prefer it sweeter, simply add a bit more powdered sweetener and whisk until it's fully dissolved.
Cover the bowl and place it in the refrigerator to chill thoroughly for at least one hour, or ideally, overnight. A well-chilled base makes for better churning.
Once your mixture is perfectly cold, pour it into the canister of your ice cream maker. Churn according to your appliance's instructions until it reaches a delightful soft-serve consistency.
Gently transfer the freshly churned ice cream into an airtight container. Place it in the freezer for a minimum of 4 hours (or until it's firm) to set completely, ensuring it's perfectly scoopable for your enjoyment.