Combine 1 ½ cups flour, ½ teaspoon baking soda and ½ teaspoon salt in a medium sized bowl and set aside.
Using a handheld electric mixer or a stand mixer fitted with the paddle attachment, cream ½ cup butter, ½ cup granulated sugar and ½ cup demerara sugar until light and smooth (2-3 minutes on medium high speed).
Add the egg and ½ teaspoon vanilla and continue beating until incorporated.
Switch to low speed and add your flour mixture a little at a time and stir until combined.
Fold white chocolate chips and pistachios. The batter will be very sticky.
Cover the bowl with plastic wrap and chill for an hour.
Preheat oven to 375F and line 2 cookie sheets with parchment paper. Scoop a tablespoon of batter into your pan and make sure to space them properly, about 2 inches apart. Do not flatten.
Bake 8-10 minutes or until the edges start to turn a light golden brown. Do not over bake.
Cool in pans for 5 minutes. Transfer to a wire rack to cool completely. This recipe yields 24-30 cookies.