Prepare the Pistachio Cream by scooping 1-tablespoon balls onto a parchment-lined baking sheet and freeze for 15-20 minutes.

Brown the Butter in a small saucepan over medium heat until it turns amber and emits a nutty aroma (about 5-7 minutes). Let cool.

Mix the Sugars and Wet Ingredients: In a bowl, whisk together cooled brown butter, light brown sugar, and granulated sugar. Add the egg and vanilla, whisk until smooth.

Combine Dry Ingredients: Sift in flour, baking powder, baking soda, and salt. Fold gently until just combined.

Incorporate Chocolate and Pistachios into the dough, distributing evenly.

Prepare for Baking by scooping portions of dough, flatten slightly, place a frozen pistachio cream ball in the center, encase with dough, and roll into a ball.

Chill the Cookie Dough in the refrigerator for at least 30 minutes.

Preheat the Oven to 350°F (175°C) and line a baking sheet with parchment paper.

Bake the Cookies for 12-14 minutes until edges are golden but centers look slightly underbaked.

Cool and Serve: Let cookies rest for 5 minutes, transfer to a wire rack to cool completely, then enjoy!