Preheat oven to 350 degrees F (180 degrees C) and arrange the oven rack to the middle position. Line baking trays with parchment.
In a medium bowl whisk together
All-Purpose Flour (2 1/2 cups)
Baking Soda (1 tsp)
Kosher Salt (1/2 Tbsp)
. Set aside.
Brown Sugar (1 cup)
Granulated Sugar (3/4 cup)
Butter (1 cup)
until light and creamy.
Add 2 whole
Large Eggs (3)
, and then an egg yolk, incorporating after each addition. Scrape bowl and mix in
Vanilla Extract (1 Tbsp)
Add flour mixture all at once and mix until incorporated. Add
Large Flake Oats (2 cups)
and mix to combine. Scrap bowl and stir in
Semi-Sweet Chocolate Chips (1 1/2 cups)
Using a 1-ounce cookie scoop, scoop the batter onto prepared trays spacing evenly at least 2-inches apart. Flatten cookies with the palm of your hand or the bottom of a cup.
Bake one tray at a time for 10-11 minutes (do not overbake). Repeat with the remaining cookie dough.
Remove from oven and allow to cool for 5 minutes on the tray before moving to a cooling rack.