Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a large mixing bowl, beat the softened butter with an electric mixer until smooth and creamy.
Add the icing sugar and continue mixing until the mixture becomes light and fluffy.
Add the vanilla extract and salt, then mix until well combined.
Gradually add the all-purpose flour and cornstarch. Mix gently until a soft dough begins to form.
Fold in the finely chopped pistachios and dried cranberries until evenly distributed throughout the dough.
Gather the dough together and shape it into a smooth log. Wrap it tightly with plastic wrap and refrigerate for at least 1 hour, or until firm enough to slice.
Remove the chilled dough from the refrigerator and slice it into even rounds about ¼-inch thick.
Arrange the cookie slices on the prepared baking sheet, leaving a little space between each one.
Bake for 10 to 12 minutes, or until the edges are lightly golden.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a cooling rack to cool completely.
