Into a small bowl, add the gelatin powder and water, and stir it with a spoon until the gelatin powder is covered with water evenly, and let it soak for 10 minutes. Set aside.
Chop the dark chocolate into small pieces to help them melt more easily in the hot cream mixture. Use a sharp knife to do so.
Pour the heavy cream, milk, granulated sugar, and salt into a saucepan over medium-low heat until the sugar dissolves mixing constantly. Heat the mixture until it reaches a light steam (bubbles around the edges of the pan) and turn off the heat. Do not let it reach a simmer!
Pour the chopped chocolate into the warm milk and cream mixture and let it sit for 5 minutes. Stir it with a wooden spoon until it's mixed and well combined and the chocolate is completely melted.
Melt the bloomed gelatin in 5-second pulses in the microwave until it's melted. Pour the gelatin into the mixture and add the vanilla extract. Mix with a wooden spoon until it's well combined.
Pass the mixture through a mesh sieve and pour it into cups using a pouring cup. Divide the mixture into 7-8 cups, depending on the size of the cups that you are using.
Store the cups in the fridge and allow them to set for at least 4 hours until the Panna Cotta looks set and has a slight jiggle to it.
Top the panna cotta with whipped cream and chocolate shavings and serve!
Notes
Use high-quality ingredients. Since the flavor of chocolate is central to this dessert, it's important to use good quality chocolate. Opt for a dark or semi-sweet variety with at least 70% cocoa for a rich and intense flavor.
Properly bloom the gelatin! Gelatin is an essential ingredient in panna cotta as it helps set the dessert. To ensure proper setting, bloom the gelatin by sprinkling it over cold water and allowing it to soften for a few minutes before adding it to the warm liquid mixture.
Incorporate flavors. While chocolate is the star of this dessert, you can enhance its taste by adding complementary flavors such as vanilla extract or a hint of espresso powder. These additions will add depth and complexity to your panna cotta.
Strain the mixture. To achieve a smooth and silky texture, strain the panna cotta mixture before pouring it into serving glasses or molds. This step helps remove any lumps or air bubbles that may have formed during preparation.
Allow the panna cotta to set for at least 4 hours. Panna cotta needs time to set properly in the refrigerator, so be patient and give it at least four hours (or overnight) to chill and firm up before serving. This will ensure that your chocolate panna cotta has the perfect consistency when you indulge in each spoonful.