Begin by grinding the roasted pistachios into a fine flour using a food processor. Aim for a consistency similar to almond meal, being careful not to over-process them into butter.

In a medium mixing bowl, combine the melted unsalted butter with both the light brown and granulated sugars. Mix well using a rubber spatula.

Add the large egg, egg yolk, vanilla extract, and almond extract (if using). Stir until the mixture is smooth and glossy, about 2 minutes.

Add the ground pistachios, all-purpose flour, baking soda, and salt to the wet mixture. Gently fold the dry ingredients into the wet.

Carefully fold in the roughly chopped white and dark chocolate pieces into the dough using a spatula.

Cover the cookie dough with plastic wrap and place it in the refrigerator to chill for at least 30 minutes.

Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper. Scoop the chilled dough into 2-ounce balls, placing them 2 inches apart.

Bake the cookies for about 12–14 minutes, watching for golden edges while the centers remain slightly gooey.

After baking, remove the cookies from the oven and allow them to cool on the baking sheet for 5 minutes.

Carefully transfer them to a wire rack to cool completely. If desired, sprinkle a touch of flaky salt on top while they're still warm.