Preheat your oven to 350°F (175°C) and prepare your baking sheet by lining it with parchment paper.

In a medium saucepan, melt 1 cup of unsalted butter over medium heat until it turns a deep golden hue, about 5-7 minutes.

In a mixing bowl, combine the browned butter, ¾ cup brown sugar, and ½ cup granulated sugar. Blend until smooth and creamy.

Beat in 1 large egg and then add 1 teaspoon of vanilla extract.

In a separate bowl, whisk together 2 cups of all-purpose flour, 1 teaspoon of baking soda, and ½ teaspoon of sea salt.

Gradually add the flour mixture to the wet ingredients, mixing on low until just combined.

Fold in 1 cup of chopped hazelnuts and 1 cup of chocolate chunks.

Drop rounded portions of cookie dough onto the prepared baking sheet, spacing them about 2 inches apart.

Bake for 10-12 minutes, until the edges are golden brown while the centers remain slightly soft.

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