Place the butter in a medium saucepan. Cook over medium heat, stirring frequently. Once the butter melts and begins to foam, continue to cook until brown specks begin to appear beneath the foam. The butter will have a nutty aroma. Remove from the heat and transfer to a glass bowl. Allow to cool about 10 minutes, or until warm to the touch but not hot.
Whisk together the flour, baking soda, salt, and orange zest. Set aside.
Using an electric mixer on medium speed, beat the butter, sugar, and brown sugar until combined. Add the egg, vanilla extract, and orange extract, and mix well.
Reduce mixer speed to low. Gradually add the flour mixture, mixing just until combined or a few streaks of flour remain.
Stir in the pistachios.
Cover and refrigerate the dough for 30 minutes.
Preheat oven to 350°F (175°C). Line baking sheets with parchment paper or silicone liners.
Using a tablespoonful of dough at a time, roll the dough into balls (squeeze the dough in your hands a few times if it's not holding together) and place on the prepared pans, leaving about 2 inches between cookies.
Bake, one pan at a time, 12 to 15 minutes, or until the edges are brown and the centers appear set.*
Cool the cookies on the pans for 5 to 10 minutes. Then transfer the cookies to a wire rack to cool completely.
