Take ¼ cup (half of the total amount) of butter, and in a small sauce pan, heat over low to medium heat to lightly brown the butter. You want it just starting to turn a light to medium brown, and don't want any dark/black bits which would add bitterness to your cookies. Place the browned butter in a heat/cold proof container and freeze for approximately 10 minutes. You would like it to be cooled, however it doesn't need to be re-solidified. Don't allow it to over harden or else you will need to soften it again.
In the bowl of your stand mixer with a batter attachment, add the remaining amount of softened butter, cooled browned butter, and sugars. Blend until thoroughly combined.
Add egg and vanilla to the stand mixer bowl, and mix until thoroughly combined.
In a separate, medium sized bowl, whisk together flour, baking soda, corn starch, and salt. Add to the bowl of the stand mixer and mix until combined.
With a spoon, stir in chocolate chips and chopped pecans. Place the dough in the fridge to cool for 30-60 minutes.
Preheat oven to 325°F and prepare a silicon or parchment paper lined baking sheet.
Remove dough from the fridge and form into small balls, approximately 2 Tbsp each. Place cookies spaced about 2 inches apart on the baking sheet. Any remaining dough can be baked in subsequent batches, or frozen to be baked another day.
Lightly press down on each of the cookie dough balls, and bake for 15-18 minutes.
Once the cookies are baked (edges turning medium brown, and slight cracking over the top of the cookie) remove from the oven and lightly salt with a large grain salt (such as sea salt, kosher salt, or flake sea salt - I typically use kosher salt). A little goes a long way, and more salt can always be added later, so take care not to oversalt your cookies.
Allow the cookies to cool 5 minutes before transfering to a cooling wrack to cool completely.