Ingredients:

  • 1 cup (2 sticks) unsalted butter, softened
  • 1 cup packed light brown sugar
  • 1/2 cup granulated sugar
  • 2 large eggs
  • 1 teaspoon vanilla extract
  • 1 3/4 cups all-purpose flour
  • 1 teaspoon baking soda
  • 1 teaspoon ground cinnamon
  • 1/2 teaspoon kosher salt
  • 3 cups old-fashioned rolled oats

Instructions:

  1. Prep the Dry Stuff: Whisk the flour, baking soda, cinnamon, and salt in a medium bowl. Set aside. Do not add the oats yet.
  2. Cream Butter and Sugars: In a stand mixer, beat the softened butter, brown sugar, and granulated sugar until the mixture is visibly lighter and fluffy (about 3 minutes on medium-high speed). This incorporates air for a softer final texture.
  3. Add Wet Ingredients: Beat in the eggs one at a time, followed by the vanilla. Scrape the bowl down thoroughly to ensure the mixture is homogenous.
  4. Incorporate Flour Mixture: Turn the mixer speed to low. Gradually add the prepared dry ingredients (flour mixture) and mix only until you see the last few streaks of flour disappearing. Do not overmix.
  5. Fold in Oats: Use a rubber spatula to fold in the 3 cups of old-fashioned rolled oats and any desired mix-ins.
  6. Chill the Dough (Crucial): Cover the dough and refrigerate for a minimum of 30 minutes (2 hours is ideal) to solidify the fat and prevent spreading during baking.
  7. Scoop and Bake: Preheat the oven to 350°F (175°C). Use a 3 Tbsp cookie scoop to portion the dough. Space them 2 inches apart on parchment-lined sheets.
  8. The Perfect Bake: Bake for 10–12 minutes. The cookies are done when the edges are set and golden brown, but the very center still looks soft and slightly undone.
  9. Finish Strong: Immediately sprinkle the warm cookies with flakey sea salt (optional). Let them rest on the baking sheet for 5 minutes before moving them to a wire rack to cool completely.