Prepare the Gelatin:

1. 1. In a small bowl, sprinkle the gelatin over the cold water and let it sit for about 5 minutes to bloom (absorb the water).
2. Heat the Cream and Milk:
   1. In a medium saucepan, combine the heavy cream, milk, and sugar. Heat over medium heat, stirring occasionally, until the mixture is hot but not boiling. Stir in the chopped chocolate and continue to stir until the chocolate is fully melted and smooth.
3. Dissolve the Gelatin:
   1. Once the chocolate mixture is smooth and fully combined, remove it from the heat. Stir in the bloomed gelatin until it is completely dissolved in the mixture.
4. Add Vanilla:
   1. Stir in the vanilla extract for added flavor.
5. Pour into Molds:
   1. Carefully pour the chocolate mixture into individual serving dishes or molds. If you prefer, you can use small ramekins or glasses.
6. Chill:
   1. Refrigerate the panna cotta for at least 4 hours, or until it has fully set. It should have a soft, creamy consistency when ready to serve.
7. Serve:
   1. Once set, gently run a knife around the edges of the panna cotta if you want to remove it from the molds, or serve it directly in the dish. Garnish with whipped cream, chocolate shavings, or berries for an extra touch of elegance.