Preheat oven to 350°F at step 8. Line two large baking sheets with parchment paper; set aside.
In a large bowl, using a whisk, beat the butter and sugars until well combined, about 2 minutes.
Whisk in the eggs one at a time and the vanilla.
In a separate large bowl, combine the flour, baking soda, cinnamon, and salt into the wet ingredients.
Add the oats, pecans, and chocolate chips.
Fold the dry ingredients into the wet ingredients, mixing just until combined.
Scoop 2-inch balls of cookie dough onto the prepared baking sheets; you should have 24 cookies.
Refrigerate the scooped cookies for 30 minutes while the oven is preheating.
Bake, one sheet at a time, in a preheated oven for 12 minutes or until cookies are golden and set at the edges and still slightly soft in the center.
Cool cookies on a baking sheet for 10 minutes before transferring them to a wire rack to cool completely.