In a mixing bowl, cream together butter, granulated sugar and brown sugar for 3-4 minutes, until like and fluffy.
Add milk, vanilla, and salt and mix to combine.
Add in the gluten-free flour about a cup at a time, mixing in between, until the flour is incorporated.
Stir in the dried cranberries and pistachios.
Scoop cookie dough out onto a piece of parchment paper and roll into a log. I like to somewhat shape it into a log with my hands and then cover with parchment paper and roll it until it becomes a log shape. The log should be about a foot long and 2 inches wide. Roll into the turbinado sugar so all side are coated. Cover with parchment paper or plastic wrap. Freeze for at least an hour.
Preheat oven to 375F. Line a baking sheet with parchment paper.
Slice cookie log into 1/4 inch pieces and place on the baking sheet. Bake for 10-12 minutes at 375F until the outer edges of the cookie just begin to brown. Let cool for 5 minutes on the pan before transferring to a wire rack to finish cooling.