Soak the pistachios in warm water for about 1 hour.
Drain and pat the pistachios dry.
Place the pistachios in a food processor and blend until smooth.
Gradually add powdered sugar while blending.
Slowly pour in the heavy cream until desired consistency is reached.
Add vanilla extract and a pinch of salt, then blend again.
Taste and adjust sweetness as needed.
Transfer the mixture to a clean jar.
Refrigerate for at least 30 minutes before serving.
Serve as a spread or topping.