Preheat oven to 350 degrees Fahrenheit. Prepare a 9x9 baking dish with parchment paper and set aside.
In a saucepan, brown the butter. Melt on low to medium heat, stirring every couple minutes until the melted butter begins to create brown bits at the bottom of the pot and it gives off a nutty scent.
Pour into a mixing bowl and let cool for a couple minutes.
Add the brown sugar and whisk together. Now add the vanilla and eggs whisking again until thoroughly combined.
Pour in the flour, cinnamon and salt. Use a wooden spoon or rubber spatula to fold in the dry ingredients until a thick brownie batter forms.
Add in all but a few tablespoons full of the chopped pecans and chocolate. Keep some to top the batter before going in the oven.
Fold in the pecans and chocolate until combined.
Pour the batter into the prepared baking dish. Sprinkle with the extra pecans and chocolate on top.
Bake in the oven for 25 minutes or until a toothpick inserted comes out clean.
Sprinkle coarse sea salt on the cookie bars straight out of the oven. Let cool for about 30 minutes before cutting.
Cut into squares.
Notes
To store, place in an airtight container or individually wrap each cut brownie square in plastic wrap.