Remove stems from each Persimon®. Using a small melon baller scoop 18 balls (medium melon baller will yield 10 balls, fewer for presentation purposes) from the flesh of each Persimon®. Reserve for garnish.
Chop the remaining Persimon® flesh into chunks and place in the bowl of a food processor and purée until smooth (approx. ½ cup).
In a small sauce pan over medium high heat, mix the rum, lemon juice, sugar and water. Simmer until the mixture is the consistency of syrup, approx. 5 minutes. Set aside to cool.
In medium saucepan, combine gelatin and sugar. Blend in milk and egg yolks; cook over medium-low heat. Stir continuously with a whisk, being careful not to overheat. When custard is slightly thickened and coats back of metal spoon remove from heat.
Whisk in Persimon® purée (approx. ½ cup), sour cream and vanilla. Refrigerate until mixture begins to thicken about 20 minutes. In large bowl, beat egg whites until stiff peaks form; fold into thickened custard. Whip whipping cream until stiff peaks form; fold into custard.
Cut the lady fingers in half. With a pastry brush, moisten the flat side of the lady with rum syrup. Line the inside of a 3 ½ inch (9 cm) ramekin with 3 lady fingers or 6 halves (unbrushed side facing out).
Fill each mold equally with the Persimon® pastry cream and refrigerate for least 2 hours.
Run a knife around the inside of the ramekin. Gently unmold the Charlottes and place on a plate.
Top each Charlotte with 3 Persimon® balls and drizzle with Rum Syrup.
Makes 6 servings.