Ingredients
Scale
- 1 cup unsalted butter, softened to room temperature
- 3/4 cup granulated white sugar
- 3/4 cup packed light brown sugar
- 1 large egg, room temperature
- 1 teaspoon pure vanilla extract
- 1 1/2 cups all-purpose flour
- 1 teaspoon baking soda
- 1/2 teaspoon salt
- 1 teaspoon ground cinnamon
- 3 cups old-fashioned rolled oats
Instructions
- Preheat your oven to 350°F (175°C). Line two large baking sheets with parchment paper or silicone baking mats. This prevents the cookies from sticking and helps them spread evenly to achieve that signature thinness.
- In a large mixing bowl, beat the softened butter, granulated sugar, and brown sugar together. Use a hand mixer or stand mixer on medium-high speed for about 2 to 3 minutes until the mixture looks light, fluffy, and pale. This aeration is vital for the cookie’s final texture.
- Add the egg and vanilla extract to the butter mixture. Beat on medium speed until fully incorporated. Scrape down the sides of the bowl with a spatula to ensure everything is evenly mixed.
- In a separate medium bowl, whisk together the all-purpose flour, baking soda, salt, and ground cinnamon. Gradually add the dry ingredients to the wet ingredients, mixing on low speed just until the flour streaks disappear. Do not overmix, as this can make the cookies tough.
- Add the old-fashioned rolled oats to the dough. Use a sturdy spatula or a wooden spoon to fold them in by hand. Ensure the oats are evenly distributed throughout the batter so every bite has a consistent crunch.
- Drop rounded tablespoons of dough onto the prepared baking sheets, spacing them at least 3 inches apart. These cookies spread significantly. Bake for 10 to 12 minutes, or until the edges are dark golden brown. The centers may still look slightly soft, but they will firm up as they cool.
- Let the cookies rest on the baking sheet for 5 minutes. Transfer them to a wire cooling rack to cool completely. As they reach room temperature, they will transform from soft to incredibly crispy and crunchy.
- Cook Time: 27 minutes