In a pot, bring water to a rolling boil. Carefully add the shelled, unsalted pistachios and let them blanch for 1 minute. Drain and rinse under cold water.

Once cooled, gently pinch each pistachio to remove its skin. Aim for complete removal of the skins.

Using a clean kitchen towel, pat the peeled pistachios dry.

Place the dried pistachios in a high-powered blender or food processor. Blend on medium speed until they form a smooth paste, about 2-3 minutes.

In a mixing bowl, combine the pistachio paste, softened unsalted butter, and granulated sugar. Blend until smooth and creamy.

In a separate bowl, combine the cold heavy cream, whole milk, vanilla extract, and sea salt. Mix gently until well combined.

Carefully fold the cream mixture into the pistachio base using a spatula.

Whip the combined mixture on medium-high speed for about 3-5 minutes, or until stiff peaks form.

For deeper flavors, consider refrigerating your pistachio cream spread for about 30 minutes.