Toast pecan halves by evenly distributing them onto a baking sheet and placing them under your oven broiler, on the center rack, for 3-5 minutes. Keep an eye on them, because they will burn quickly.
After you've toasted the pecans, turn the broiler off and preheat the oven to 350℉. While your Pecans cool, cream together the butter and brown sugar and follow by adding in the egg and vanilla extract, scraping the sides a couple of times to ensure thorough incorporation.
In a separate bowl, whisk together the dry ingredients, then add about 1/4 of the dry into the wet and mix on a low speed. Continue adding the dry ingredients, scraping down the sides as you go, and being careful to not over mix.
Measure the oats, chocolate chips, and the cooled pecans into the batter and mix on a quick speed for about 5 seconds to evenly disperse them into the dough.
Baking
Using a ⅛ Cup measurer or two-tablespoon cookie scoop, measure out your cookies onto baking sheets, leaving about 3 inches between cookies, as these will spread. Do not push them down at all, just leave them in balls.
Bake your cookies for 12-15 minutes, or until the edges begin to brown.
Allow the cookies to cool on the pan about 5 minutes before moving to a cooling rack.