Soften the Butter: Place the room-temperature salted butter into a mixing bowl. Use a wooden spoon to beat it lightly until it's even softer and creamy, about one minute.

Combine Sugar and Butter: Add the granulated sugar to the softened butter. Beat them together carefully until thoroughly mixed.

Mix in Flour: Gradually add the all-purpose flour. Use your hands to mix until the dough starts to come together.

Add Pistachios: Roughly chop the pistachios and fold in ⅔ of them into the dough. Reserve the remaining nuts for later.

Chill the Dough: Shape the dough into a log and wrap it tightly in plastic wrap. Chill in the refrigerator for one hour.

Preheat the Oven: Preheat your oven to 320°F / 160°C. Line a cookie sheet with parchment paper.

Slice the Dough: After chilling, slice the dough into rounds approximately ½ inch thick and place the rounds on your cookie sheet.

Bake the Cookies: Bake in the preheated oven for 20-25 minutes until golden brown. Allow to cool for 10 minutes before transferring.

Melt the Chocolate: In a microwave-safe bowl, melt the dark chocolate in 30-second increments until smooth.

Drizzle and Garnish: Dip half of each cooled cookie into the melted chocolate, lay them on parchment, and sprinkle reserved pistachios on top.