In a medium saucepan, melt the butter over medium heat and brown it for 5-7 minutes.

In a large mixing bowl, whisk together flour, baking soda, and salt.

In a stand mixer, combine the cooled brown butter, dark brown sugar, and granulated sugar, beat until smooth.

Add eggs one at a time and then the vanilla extract, mixing well.

Gradually mix the dry ingredients into the wet mixture until just combined.

Fold in the chocolate chips and dark chocolate chunks carefully with a spatula.

Chill the dough covered for 30 minutes in the refrigerator (optional).

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

Scoop dough onto the baking sheet, spacing them apart, and bake for 10-12 minutes.

Remove from oven, sprinkle with sea salt flakes, and cool on a wire rack.