In a medium bowl, whisk together the all-purpose flour, baking soda, and salt. Set aside.

In a large bowl using an electric mixer, cream the softened butter, brown sugar, and granulated white sugar together on medium-high speed until light, fluffy, and pale in color (about 2-3 minutes).

Add the room-temperature egg and vanilla extract to the butter mixture. Beat on medium speed until well combined.

Turn the mixer to low speed and gradually add the dry flour mixture to the wet ingredients. Mix just until the flour disappears. Do not overmix.

Using a spatula, gently fold in the white chocolate chips, dried cranberries, and chopped pistachios until evenly distributed.

Cover the dough tightly with plastic wrap and chill in the refrigerator for at least 1 hour (or up to overnight) to prevent cookies from spreading too much.

Preheat oven to 350°F (175°C). Line large baking sheets with parchment paper or silicone baking mats.

Scoop 1.5 to 2 tablespoons of dough per cookie, roll into balls, and place 2 inches apart on the prepared baking sheets. (Optional: press extra chips, cranberries, and nuts on top for presentation).

Bake for 10-12 minutes, or until the edges are lightly golden but the centers are still soft and slightly underbaked.

Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.