Place the prunes in a non-reactive saucepan with water or juice. Bring to a simmer over medium heat; simmer for 20 minutes and prunes begin to soften. Drain the prunes, reserving 1 cup of the liquid from the pan. Place the prunes into a food processor or use an immersion blender and process into a smooth puree'.

Return the puree' to the saucepan along with the 1 cup reserved liquid, the sugar, the cinnamon, lemon rind and lemon juice. Bring to a simmer and cook, stirring frequently until the mixture begins to bubble. Once the mixture darkens and thickens into the consistency of lemon curd, remove from the heat, add the vanilla extract and cool completely. You can store the prune filling in a glass canning jar in the refrigerator for several weeks or you can also can the prune filling in sterilized jars and process in a hot water bath. This will keep the filling for many months.