In a small bowl, sprinkle the powdered gelatin over the cold water. Let it sit for about 5 to 10 minutes to bloom.

In a medium saucepan, combine the heavy cream, whole milk, and granulated sugar. Heat over medium heat, stirring occasionally, until the mixture is hot but not boiling, and the sugar has dissolved completely.

Once the cream mixture is heated, remove it from the heat. Add the vanilla extract and stir well.

Add the bloomed gelatin to the warm cream mixture, stirring until the gelatin is completely dissolved.

Pour the panna cotta mixture into individual serving cups or molds. Allow it to cool at room temperature for about 30 minutes.

Once cooled, cover the cups with plastic wrap and refrigerate for at least 4 hours, or until the panna cotta is set.

To serve, run a knife around the edges of the panna cotta if using molds, then invert onto a plate. If served in cups, simply garnish with fresh berries and mint leaves.

Enjoy your creamy and delicious panna cotta!