Place water in a small bowl. Sprinkle gelatin over water. Let stand 5 minutes to soften gelatin.

Place cream, sugar, and chocolate in a heavy medium sauce pan. Bring to medium high heat then let simmer until sugar dissolves and chocolate is melted. Remove pan from heat, and  add the gelatin and whisk until dissolved. Cook for two more minutes on low heat.Take the pan off the heat, add the vanilla and let cool for 5 minutes. Whisk in the mascarpone cheese until everything is blended smoothly.

Ladle into containers. Small martini glasses, ramekins, mason jars. Be creative. Refrigerate 4 hours. 

In a medium saucepan, bring the cherries, sugar, and port to a boil over medium-high heat, stirring often. In a small bowl, stir the lemon juice and cornstarch together until smooth. Whisk it into the boiling cherry mixture.
Return to a boil, stirring constantly. You don’t want this sauce to scorch on the bottom.Cook until the liquid has thickened, which should take about 1 more minute.
Remove the pot from the heat and taste. You can add a little extra sugar or lemon juice if needed at this point, depending on your personal taste. Cool and use to garnish the panna cotta when serving.