Preheat your oven to 350°F (175°C).
In a medium bowl, whisk together the all-purpose flour, finely ground pistachios, and salt.
In a large mixing bowl, beat the softened unsalted butter and 1 cup of powdered sugar together using an electric mixer until light and fluffy, about 3-4 minutes.
Pour in the vanilla extract and mix until well combined.
Gradually add the dry ingredients to the butter mixture, mixing on low speed until just combined.
Using a cookie scoop, portion out the dough and roll it into balls. Place them on a parchment-lined baking sheet.
Bake for 12-15 minutes, or until the edges are lightly golden.
Once baked, roll the cookies in the remaining powdered sugar while they are still warm.
Transfer the cookies to a cooling rack and let them cool completely.
