In a medium saucepan over medium heat, melt the unsalted butter, stirring frequently. Watch carefully as it foams and turns a nutty brown, around 5-7 minutes. Remove from heat and let it cool for about 5 minutes.

Transfer the browned butter to a large mixing bowl. Add the light brown sugar and granulated white sugar, mixing until smooth and creamy. Beat in the egg and vanilla extract until the mixture is glossy.

In a separate bowl, whisk together the flour, baking soda, and fine sea salt. Slowly fold the dry ingredients into the wet mixture using a spatula until just combined.

Gently fold in the white chocolate chips and freeze-dried raspberries to the dough until evenly distributed.

Using a tablespoon, portion out the dough onto parchment-lined baking sheets, spacing them about 2 inches apart. Preheat your oven to 350°F (175°C) and bake the cookies for 12-14 minutes.

Once baked, remove the cookies from the oven, allowing them to cool on the baking sheet for about 5 minutes. Then transfer them to a wire rack to cool completely.