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Overhead shot of colorful oatmeal M&M cookies

Easy, One Bowl Chewy Oatmeal Chocolate Chip Cookies

5 from 14 votes
These big, chewy oatmeal chocolate chip cookies are made in one bowl, don't require a stand mixer, don't need chilling, ready in 30 minutes, and are easily customizable to whatever add ins you like or have on hand!
Prep Time 10 minutes
Cook Time 11 minutes
Total Time 21 minutes
Servings 12 large cookies


  • ½ cup unsalted butter, very soft
  • 1 large egg, room temperature
  • ½ cup light brown sugar, packed
  • ¼ cup granulated sugar
  • 1 Tablespoon pure vanilla extract or vanilla bean paste, (yes, tablespoon!)
  • 1 ½ cups old-fashioned rolled oats, not instant or quick cook
  • ¾ cup all-purpose flour
  • ½ teaspoon baking soda
  • ½ teaspoon cornstarch
  • ½ teaspoon salt, or to taste
  • ¼ teaspoon ground cinnamon
  • 1 cup semi-sweet chocolate chips, plus more for topping (can substitute the entire amount or partial amount for a combination of mini chocolate chips, M&Ms, mini M&Ms, chopped chocolate, white chocolate chips, dried cranberries, or raisins)
  • Sea salt for topping, optional


  • Preheat oven to 350°F and line two baking sheets with a nonstick silicon mat or parchment paper. Set aside.
  • In a large bowl, combine butter, egg, brown sugar, granulated sugar and vanilla. Using either a wooden spoon or a hand mixer on low-medium speed, stir to combine until smooth and a bit fluffy.
  • Add oats, flour, baking soda, cornstarch, salt and cinnamon and stir again to combine.
  • Add chocolate chips (or preferred add ins) and stir one more time until just combined.
  • Using a large cookie scoop (about 3 Tablespoons), portion mounds of cookie dough on prepared baking sheets at least 2" apart.
  • Bake for 11 minutes or until the tops have just set - you want them to be ever so slightly underbaked, as they'll continue to set as they cool. If you chilled the dough, add another minute or two to the baking time.
  • Top each cookie with a few more chocolate chips (or other add ins) for presentation's sake, then let cool completely on the baking sheet.
  • Serve and enjoy!



Chill or Freeze Dough: Store the dough covered in the fridge for up to 1 week, or store portioned dough balls in an airtight container in the freezer for up to 3 months. Let come to room temperature before baking, or bake them straight from the fridge or freezer, just give them a couple more minutes in the oven.


Calories: 281kcal | Carbohydrates: 34g | Protein: 4g | Fat: 15g | Saturated Fat: 8g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 4g | Trans Fat: 1g | Cholesterol: 35mg | Sodium: 154mg | Potassium: 151mg | Fiber: 2g | Sugar: 19g | Vitamin A: 264IU | Vitamin C: 1mg | Calcium: 28mg | Iron: 2mg
Course Cookies
Cuisine American
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