In a medium saucepan, melt the unsalted butter over medium heat. Stir continuously until the butter turns golden brown and smells nutty, about 5-7 minutes. Be careful not to let it burn!

In a large mixing bowl, combine the brown sugar and granulated sugar. Add the browned butter once it has cooled slightly, and mix until combined.

Mix in the vanilla extract, egg, and egg yolk until the mixture is smooth.

In a separate bowl, whisk together the all-purpose flour, baking soda, and salt. Gradually incorporate this mixture into the wet ingredients until fully combined.

Gently fold in the chocolate chips, ensuring even distribution throughout the dough.

For a deeper flavor, chill the dough in the refrigerator for about 30 minutes (optional).

Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.

Scoop tablespoons of dough onto the prepared sheet, spacing them about 2 inches apart.

Bake for 10-12 minutes, or until the edges are golden and the centers look slightly underbaked.

Let the cookies cool on the baking sheet for about 5 minutes before transferring them to a wire rack.