Brown the Butter: In a medium saucepan, melt the butter over medium heat, stirring constantly for about 5 minutes until it turns golden brown. Remove from heat and cool for approximately 10 minutes.

Mix Dry Ingredients: In a mixing bowl, whisk together flour, baking soda, and salt.

Cream Sugars and Butter: Transfer the cooled browned butter to a mixing bowl. Add dark brown sugar and granulated sugar, then beat on medium speed for 2-3 minutes until light and fluffy.

Add Wet Ingredients: Crack in eggs one at a time, mixing well, and then add vanilla extract until combined.

Combine Wet and Dry Ingredients: Gradually add dry mixture to wet ingredients, folding gently until just combined.

Fold in Chocolates: Add chocolate chips and chunks, mixing gently until spread evenly.

Chill the Dough: Wrap the dough in plastic wrap and refrigerate for at least 30 minutes.

Preheat Oven: Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.

Bake Cookies: Scoop dough onto the prepared baking sheet, spacing them 2 inches apart. Bake for 10-12 minutes until edges are golden and centers remain soft.

Finish with Sea Salt: Sprinkle warm cookies with sea salt flakes, allow to cool slightly, then transfer to a wire rack to cool completely.