Cube the butter into small cubes and place it into a small saucepan.

Melt the butter over medium heat. Once melted, reduce heat to medium-low.

Cook until the butter turns a golden-brown color, then strain through a fine-mesh strainer.

Chill the browned butter in the refrigerator for about 1 to 1 ½ hours until cooled.

Preheat the oven to 375F° and line a baking sheet with parchment paper.

Pour the cooled, browned butter into a large mixing bowl. Add sugars and cream together for about 4 minutes.

Add eggs and vanilla, then beat again for a few minutes.

In a separate bowl, combine flour, baking soda, sea salt, and dried milk powder. Add this to the creamed mixture.

Fold in white chocolate chips and chopped pistachios.

Using a large measuring scoop, drop cookie dough onto the prepared baking sheet.

Bake the cookies at 375F° for exactly 10 minutes.

Immediately sprinkle with sea salt flakes and gently flatten each cookie.

Shape each cookie into a nice round shape to thicken the edges.

Transfer cookies to a wire rack to cool completely.

Allow cookies to cool before enjoying with coffee, tea, or milk.

Store leftover cookies in an airtight container at room temperature.

For freezing, wrap cookies in plastic before placing into an airtight freezer container.