In a small bowl, sprinkle the gelatin over cold water and let it bloom for 5 minutes.
In a saucepan over medium heat, combine the heavy cream, milk, and sugar. Stir until the sugar is dissolved and the mixture is heated, but not boiling.
Remove from heat and stir in the vanilla extract and pistachio paste until well combined.
Add the bloomed gelatin to the warm mixture and stir until it is completely dissolved.
Pour the mixture into four serving glasses or molds. Allow it to cool slightly before covering with plastic wrap.
Refrigerate for at least 4 hours or until set.
To serve, top with crushed pistachios and enjoy.