Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a large bowl, cream together the softened unsalted butter and powdered sugar until light and fluffy. Add vanilla extract and mix thoroughly.

In a separate bowl, whisk together the all-purpose flour, baking powder, salt, and optional cornstarch.

Gradually add the dry mixture to the creamed butter mixture, mixing until a cohesive dough forms.

Gently fold in the finely chopped pistachios and dried cranberries.

Shape the dough into small balls, then create the wreath form by making a hole in the center of each ball.

Arrange the shaped cookies on the prepared baking sheet and bake for 12-15 minutes until the edges turn light golden brown.

Transfer the cookies to a wire rack to cool completely. Decorate with additional chopped pistachios and dried cranberries, then dust lightly with powdered sugar.