Line a 9 x 9 inch pan with parchment paper leaving enough to hang from the sides. Preheat oven to 325 degrees F.

Place the chopped chocolate in a medium sized mixing bowl.

Melt the butter in a saucepan over medium heat. Use a light colored pan if possible as this will help you better notice the butter change color. Stir it constantly. It will start to foam. Continue stirring as you watch for it to turn to a light, amber color then a medium brown and develop a nutty smell which should happen in about five minutes. Pour the brown butter over the chopped chocolate and stir until chocolate has melted completely. Allow to cool slightly.

In a medium bowl, whisk to combine the flour, cocoa, and salt. Set aside.

In the bowl of a stand mixer fitted with the whisk attachment, beat together the sugars, eggs and vanilla on high speed until mixture has thickened and lightened in color, about 3-4 minutes .

With the mixer on low, slowly stream in the slightly cooled chocolate and brown butter mixture.

Stir in the dry ingredients til just combined. Fold in the chocolate chips.

Pour the brownie batter into the pan and use a spatula or offset spatula to evenly spread out the brownies and smooth out the top. Bake for 40- 50 minutes until a toothpick when inserted in the center comes out clean and with only a few crumbs. Keep in mind the brownies will continue to cook slightly when out of the oven, so do not over bake them. Place pan on a wire rack and allow brownies to cool completely in the pan before slicing.