Preheat your oven to 350 degrees Fahrenheit and grab 2 baking sheets, lining them with parchment paper.
Using a mixer begin to beat together your butter and sugars, creating a creamy and indulgent base for your cookies.
Add in the instant pistachio pudding mix, the eggs and the vanilla extract and mix together until combined.
In a separate bowl, whisk together the baking soda, salt and flour together. This will add structure and balance to your cookies, ensuring they come out perfectly chewy and delicious.
Add the dry ingredients to the wet ingredients, mixing together until just combined. Mix/fold in the white chocolate chips and chopped pistachios.
Using a medium or large cookie scoop, scoop cookie dough scoops onto the prepared baking sheet. Add more white chocolate chips and pistachios to tops if desired.
For medium-sized cookies (about 2 tablespoons) bake cookies 10-12 minutes. For ¼ cup cookies, bake cookies 13-15 minutes.
When they’re ready, pull the golden-brown cookies out of the oven and let them cool on the baking sheet for two minutes. This allows them to set and ensures they maintain their chewy texture. Then, with a spatula, transfer them to a cooling rack, to cool completely.