1-First Step: Mise en place and dry mix Gather ingredients and set the oven racks in the middle position. Measure each ingredient before starting. In a medium bowl whisk together 1 ⅔ cups all purpose flour, 3.4 ounces instant pistachio pudding mix (1 box), 1 teaspoon baking soda, and ½ teaspoon salt. Set this dry mixture aside so it is ready to add to the butter-sugar mixture.

2-Second Step: Creaming the butter and sugars In a large bowl, use a hand mixer or stand mixer fitted with the paddle attachment to cream ¼ cup light brown sugar, ¾ cup granulated sugar, and ¾ cup unsalted butter (softened) until the mixture is light and fluffy. This typically takes about 3 to 5 minutes at medium speed. Scrape down the sides of the bowl as needed so everything mixes evenly.

3-Third Step: Add egg and vanilla Add 1 egg (room temperature) and 1 teaspoon clear vanilla extract to the creamed mixture. Beat at low to medium speed until well blended, about 30 to 60 seconds. The dough should look cohesive and slightly glossy.

4-Fourth Step: Combine dry and wet ingredients Gradually add the dry mixture to the wet bowl, mixing on low speed until just combined. If you want a deeper pistachio color, stir in a few drops of green or blue food coloring at this stage and mix until the color is even but not overworked. Keep the mixing gentle to avoid developing gluten and making the cookies tough.

5-Fifth Step: Fold in the mix-ins Using a spatula, fold in 1 cup white chocolate chips and ½ cup chopped pistachios until distributed evenly through the dough. The dough will be slightly sticky but workable.

6-Sixth Step: Chill the dough Refrigerate the dough for at least 30 minutes. Chilling helps solidify the butter and control spread so the cookies bake thick and have a soft center. If you are short on time, a 15 minute chill helps but 30 minutes is best for texture.

7-Seventh Step: Preheat and prepare to bake Preheat the oven to 325°F and line a baking sheet with parchment paper or lightly grease it. For a thicker cookie you may bake at 350°F for 8 to 9 minutes; for a more classic, slightly flatter shape bake at 325°F for 11 to 14 minutes. These alternative temperatures are useful depending on how tall or flat you want the final cookie.

8-Eighth Step: Portion and bake Scoop out rounded tablespoons of cookie dough and place them on the prepared baking sheet about 2 inches apart. Bake for 12 to 14 minutes or just until set. Remove immediately if edges begin to brown since residual heat will keep cooking the cookies. For the 350°F option bake 8 to 9 minutes total.

9-Final Step: Finish and cool After removing the baking sheet from the oven, gently press a few extra white chocolate chips into the top of each cookie for a pretty finish. Allow cookies to cool on the baking sheet for several minutes before transferring them to a wire rack to cool completely. This short rest lets the cookies set without breaking apart.