In a large bowl with a hand mixer or the bowl of a stand mixer, cream butter, brown sugar, and sugar until light and fluffy. Add egg and vanilla and mix until combined.
In a separate bowl, combine the flour, cornstarch, baking soda and salt. Gradually add to the butter mixture and mix until almost combined. Add the caramel chips, chocolate chips, and pecans and mix until combined. Cover and chill cookie dough for 1 hour or over night.
Preheat oven to 350 and line a large cookie sheet with parchment paper or a silicone baking mat.
Using a medium cookie scoop, drop rounded balls of cookie dough baking sheet. Bake for 9-10 minutes, edges will be slightly browned. Add a couple extra chocolate chips to the tops before they cool.
Let cookies cool for 5 minutes on the cookie sheet before removing to a cooling rack.
Feel free to use a mixture of chocolate and/or caramel chips and pecans or even walnuts that equals 1 1/2 cups.