Line 2 to 3 baking sheets with parchment paper or Silpat liners.  Set aside.

In a medium-sized bowl, whisk together pistachios, flour and salt. Set aside.

Using a standing or hand-held mixer and a large bowl, cream the butter and 1/2 cup powdered sugar together until smooth.  Add the vanilla and almond extract, beating to combine.  On low speed, stir the pistachio mixture into the butter mixture until just combined.  Be sure to scrape the sides and bottom of the bowl to make sure all ingredients are evenly combined.

Using a tablespoon or a #50 ice cream scoop (2 tbsp.), portion dough and roll into balls.  Place about 1-inch apart on the prepared baking sheets.  Refrigerate dough for about 30 minutes.  Preheat oven to 350 degrees F while dough is chilling.

Bake cookies for 10-15 minutes or until cookies are set, appear dry and are light golden brown.  Remove from the oven and let rest on the pan for about 5 minutes.  Place cookies on a wire rack to cool until just warm.

Place 1 cup of powdered sugar into a bowl or a zip-top gallon-sized bag.  Roll each cookie in powdered sugar and allow to cool completely.  Cookies can be rolled in powdered sugar up to 3 times.  Store cookies in an air-tight container for up to 7 days or freeze for up to 3 months.