In a medium saucepan, combine the heavy cream, whole milk, sugar, vanilla bean paste, and a pinch of salt. Heat over medium heat, stirring constantly, until the sugar has dissolved and the mixture is hot but not boiling (about 5-7 minutes).
Meanwhile, in a small bowl, sprinkle the gelatin over the cold water and let it sit for about 5 minutes to bloom.
Once the cream mixture is hot, remove it from the heat and stir in the bloomed gelatin until fully dissolved.
Allow the mixture to cool slightly for about 10 minutes, stirring occasionally.
Once slightly cooled, pour the mixture into individual serving cups or ramekins.
Cover with plastic wrap and refrigerate for at least 4 hours, or until set completely.
To serve, gently run a knife around the edge of the panna cotta to loosen it, and if desired, invert onto a plate. Garnish with fresh berries and a sprig of mint.
Notes
For best results, allow the panna cotta to set overnight.