Preheat oven to 350°F.
Line a baking sheet with parchment paper and set aside.
Beat butter and sugar for 2 minutes with mixer on medium speed.
Add in egg, yolk, vanilla extract, baking soda, and salt. Mix until combined, scraping sides of bowl as needed.
Beat in pudding mix for about 30 seconds.
Add flour, mixing on low until combined.
Finally, add chips and mix until distributed.
Use a medium-sized cookie scoop to portion cookies. Place cookies onto prepared baking sheet 2″ apart.
Bake for 8-10 minutes until cookies are almost set. Overbaking will yield a harder, drier cookie.
Allow cookies to cool on baking sheet for about 5 minutes before moving to a wire rack to cool completely.