Preheat oven to 350 degrees and line a large baking sheet with parchment paper.
Place room tempterature butter into a stand mixer fitted with the paddle attachment . Add to the butter the brown and granulated sugar. Beat to combine then add egg and vanilla extract.
Add your all purpose flour, vanilla pudding mix, baking soda, corn starch, salt and mix on low until just combined.
Mix in dark chocolate and chopped pecans
Using a standad cookie scoop (2.5 tablespoon scoop) scoop the cookies onto your prepared baking sheet.
Place the cookies in the freezer for 15 minutes before baking.
Remove the cookies from the freezer and make sure they're about 2 inches apart from each other on a parchment lined baking sheet. At this time, you can sprinkle them with a little sea salt if desired.
Bake them for about 14 minutes.
Allow them to cool slightly for about 5-10 minutes before transferring to a wire rack to continue cooling.