Place butter in a small saucepan over medium heat. Cook, stirring frequently, until melted, foamy, and golden brown with a nutty aroma. Remove from heat and cool slightly.

Whisk browned butter, brown sugar, and granulated sugar together until smooth. Add egg and vanilla and mix until well combined.

Stir in flour, baking soda, and salt until a soft dough forms.

Gently fold in blueberries and white chocolate chips if using.

Cover dough and refrigerate for 20 to 30 minutes.

Preheat oven to 350°F and line a baking sheet with parchment paper.

Scoop dough into balls and place about 2 inches apart on the prepared baking sheet.

Bake for 10 to 12 minutes until edges are lightly golden and centers are set.

Cool on the baking sheet for several minutes before transferring to a wire rack.