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

In a large mixing bowl, combine softened unsalted butter, brown sugar, and granulated sugar and beat on medium speed until smooth and fluffy, about 2-3 minutes.

Add the large egg and vanilla extract, mixing on low speed until fully incorporated.

In a separate bowl, whisk together all-purpose flour, baking soda, and salt until light and airy.

Gradually add the dry ingredients to the wet mixture, mixing on low speed until just combined.

Fold in the white, milk, and dark chocolate chips along with the chopped pistachios.

Scoop portions of dough onto the prepared baking sheet, leaving about 2 inches between each cookie.

Bake for 10-12 minutes until edges are golden brown but the centers remain soft.

Let the cookies cool on the baking sheet for about 5 minutes before transferring to a wire rack.