Cover the bowl tightly and refrigerate the dough for at least 2 hours. Chilling prevents excessive spreading and develops a richer flavor.
Step 5: Bake the Cookies
Preheat the oven to 350°F (175°C).
Line two baking sheets with parchment paper.
Using a medium cookie scoop (about 1.35 ounces), scoop portions of dough onto the baking sheets, leaving about 3 inches between each cookie.
Sprinkle each cookie with the reserved ground pistachios.
Bake the Salted Pistachio Chocolate Chunk Cookies for 10–12 minutes until the edges are lightly golden while the centers remain soft.
Allow the cookies to cool on the baking sheet for 1 minute before transferring them to a wire rack.
Finish with a light sprinkle of flaky sea salt, if desired.