Preheat your oven to 350°F (175°C) and prepare a 9×13 inch baking dish by lining it with parchment paper.

In a medium saucepan, melt the unsalted butter over medium heat, stirring constantly until it foams and turns a golden brown, about 5-7 minutes.

Remove from heat and let it cool slightly.

In a large mixing bowl, combine the brown sugar and granulated sugar, then pour in the browned butter, followed by the eggs and vanilla extract. Mix well until smooth.

In a separate bowl, whisk together the all-purpose flour, baking soda, and salt. Gradually incorporate this mixture into the wet ingredients, stirring until just combined.

Fold in the chocolate chips and chopped pistachios, ensuring they’re evenly distributed throughout the batter.

Pour the batter into your prepared baking dish, spreading it evenly. Bake for 25-30 minutes or until a toothpick inserted in the center comes out clean.

Allow the cookie bars to cool in the pan for about 10 minutes before lifting them out using the parchment paper. Let them cool completely on a wire rack, then cut into squares and enjoy!