Preheat the oven to 350 degrees F. 

In a small bowl, whisk together the flour, baking soda and salt. Set aside.

On medium heat, place a non stick skillet and add butter to melt.  Cook and allow the butter to melt down and bubble, stirring occasionally, until brown bits begin to appear on the bottom. Once the brown bits appear, turn the heat off and continue to stir for about 30 seconds. MAKE SURE to let the butter cool slightly. With a pastry brush, dip in melted browned butter and butter the bottom and sides of a 9×13 inch baking dish.

In a large mixing bowl, add brown sugar, then pour in the brown butter and mix until combined combined and smooth – the sugar will somewhat dissolve.  One at a time, add the eggs, stirring immediately making sure they do not cook.  This is why we must make sure the browned butter is cooled before adding the eggs.  Next, stir in the vanilla extract.

Lastly, with a wooden spoon, stir in the dry ingredients until combined. Add in the chocolate chips and mix until thoroughly mixed through.

Now is time to press the mixture into the buttered dish.  Bake for 25 to 30 minutes, or until the top is golden brown and set in the center.  Remove the dish and immediately sprinkle the top with sea salt. Allow to cool completely before slicing into bars.