In a small saucepan over medium heat, combine the prunes and water. Bring to a simmer then cover and cook until the prunes are meltingly tender, about 15 minutes.
Transfer the mixture to a food processor fitted with the “S” blade. Add the kosher salt, vanilla, and one (1) tablespoon sugar. Blend until the mixture is thick and buttery.
Taste and add additional sugar, one tablespoon at a time until desired sweetness level is achieved.