Preheat oven to 350 degrees Fahrenheit. Line a cookie sheet with parchment paper.
Add butter, light brown sugar, vanilla extract, vegetable oil, sour cream, and eggs to a large mixing bowl. Whisk ingredients until the mixture is creamy.
Add white cake mix and salt to the mixing bowl. Stir to combine with the wet ingredients. Fold in pecans (optional) and chocolate chips.
Use a cookie scoop to remove about 1 to 1 ½ Tbsp of chocolate chip cookie dough from the bowl. Shape into a ball, and then flatten the ball slightly.
Repeat step 4 for the remaining cookie dough, until all of the cookie dough has been shaped into rounds. (If desired, cover and refrigerate the cookie dough rounds for 30 minutes to 1 hour before baking to let the dough rest and absorb moisture. Or, bake the cookies right away.)
When ready to bake, place the chocolate chip cookie dough rounds on a cookie sheet to bake. Leave 2 inches between each cookie on all sides. (It may be necessary to bake cookies in batches, depending on the size of the cookie sheet.)
Bake the chocolate chip cake mix cookies on the center oven rack for 8 to 10 minutes, or until a toothpick inserted into the center of the cookies comes out clean.
After removing the cookie sheet from the oven, let the cookies rest on the cookie sheet for 5 minutes. Use a spatula to move the cookies to a cooling rack to cool before serving.