Ingredients
Equipment
Method
- Position the oven rack in the middle position and heat to 350°F (175°C), then line a light-colored aluminum half-sheet pan with parchment paper and set aside.
- Add the 1 cup (226g) softened unsalted butter, 3/4 cup (150g) packed brown sugar, and 1/2 cup (100g) granulated cane sugar to the bowl of a stand mixer fitted with the paddle attachment (or a large bowl with a hand mixer) and beat on medium speed for 3 full minutes until pale, fluffy, and increased in volume.
- With the mixer on low, add the 2 room-temperature large eggs one at a time, waiting 30 seconds between each addition until fully incorporated, then add 1 tsp pure vanilla extract and mix for 15 seconds, scraping down the sides and bottom of the bowl with a silicone spatula before continuing.
- In a separate small bowl, whisk together the 1½ cups (180g) all-purpose flour, 1 tsp baking soda, 1 tsp ground cinnamon, and 1/2 tsp fine sea salt until evenly combined, then add the dry mixture to the butter mixture all at once and mix on low speed for 15 seconds until just combined with no visible dry flour streaks remaining.
- Add the 3 cups (270g) old-fashioned rolled oats to the dough, switch to a silicone spatula, and fold by hand using slow strokes from the bottom of the bowl upward for approximately 15–20 folds until no dry patches remain and the dough holds together in a cohesive mass — do not use the mixer for this step.
- Scoop 3 tablespoons (approximately 69g) of dough per cookie, weigh the first one to calibrate, and place the dough balls at least 2 inches (5cm) apart on the prepared pan — do not flatten — then bake at 350°F (175°C) for 10 to 12 minutes until the edges are set and lightly golden and the centers still look slightly soft and underdone.
- Leave the cookies on the hot pan for exactly 5 minutes without moving them, then transfer to a wire cooling rack using a thin spatula and cool completely to room temperature — approximately 30 minutes — before glazing.
- Sift the 1½ cups (180g) powdered sugar into a medium bowl, add the 3 tbsp (45ml) whole milk and 1/2 tsp pure vanilla extract, and whisk until completely smooth and falling from the whisk in a slow steady ribbon that settles flat within 5 seconds — adjust with milk ½ tsp at a time if too thick or powdered sugar 1 tbsp at a time if too thin.
- Place the cooled cookies on a wire rack over parchment paper, spoon approximately 1½ tsp of glaze onto the center of each cookie and let it spread naturally toward the edges, then allow to set at room temperature for 20–25 minutes until fully opaque and firm before stacking or storing.
Notes
- Oats: use old-fashioned rolled oats only — quick oats dissolve into the dough and produce a smooth, textureless cookie with no visible oat surface.
- Butter: must be softened to 65–68°F — too warm = flat spreading cookies, too cold = dense under-aerated dough.
- Baking soda: test freshness before baking — drop ½ tsp into hot water + vinegar, it must bubble aggressively within 2 seconds.
- Glaze: sift powdered sugar before mixing — unsifted lumps create a streaky, uneven finish on the cookie surface.
- Glazing: cookies must be fully cooled to room temperature before glazing — warm cookies cause the glaze to slide off completely.
- Storage: lidded hard-sided container, parchment between layers, room temperature up to 4 days — do not use zip-lock bags.
- Freeze unbaked: portion into 69g balls, freeze solid on a pan, transfer to a freezer bag — bake from frozen at 350°F for 13–15 minutes.
- Make ahead: bake and glaze the day before serving — cinnamon flavor deepens overnight and Day 2 texture is better than Day 1.
- Scaling: doubles cleanly — use only 1½ tsp baking soda for a doubled batch, not 2 tsp.
- Altitude: above 3,500 ft — reduce baking soda to ¾ tsp, add 2 tbsp flour, reduce each sugar by 1 tbsp, check at 9 minutes.
- Allergens: contains gluten, dairy, and eggs. For gluten-free, use a certified 1:1 GF flour blend and certified gluten-free oats.
- Tip: bake one test cookie first — evaluate spread before committing the full batch to the oven.