Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking dish or line it with parchment paper for easy removal.
In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.
Add the eggs one at a time, mixing well after each addition, then stir in the vanilla extract.
In a separate bowl, whisk together the pistachio pudding mix, flour, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Fold in the chopped pistachios and white chocolate chips.
Spread the cookie dough evenly in the prepared baking dish.
Bake for 25-30 minutes or until the edges are golden and a toothpick inserted in the center comes out clean.
Let cool in the pan for about 10 minutes before transferring to a wire rack to cool completely.
Once cooled, cut into bars and serve.