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One-Bowl, No-Mixer, Extra-Large Oatmeal Chocolate Chip Cookie

One-Bowl, No-Mixer, Extra-Large Oatmeal Chocolate Chip Cookie — A FAST and EASY recipe for ONE XL soft and chewy very THICK cookie loaded with chocolate!! No mixer needed and so DELISH!!

Giant Cookie Recipe
I have dozens of recipes for oatmeal cookies and recently had a craving for them. Rather than making a whole batch of cookies that I would no doubt eat within a few days, I exercised some self-control and made one extra-large cookie.
My craving was handled on the spot and I didn’t have another 18 cookies starting back at me on the counter. Win-win.
Other wins about this recipe include that it’s made in one bowl and without a mixer. This giant cookie is wonderfully soft but the oats give it chewiness.
And of course there is chocolate galore. Not sure if this is a splurge cookie for one or a be-nice-and-share-some kind of cookie for two but it weighed about a half pound and my hand could’t even fit around it. Not complaining.

What’s in This Big Oatmeal Chocolate Chip Cookie?
To make this single serve cookie recipe, you’ll need:
- Egg yolk
- Unsalted butter
- Granulated sugar
- Light brown sugar
- Vanilla extract
- Old-fashioned oats
- All-purpose flour
- Baking soda
- Cornstarch
- Kosher salt
- Semi-sweet chocolate chips

How to Make a Giant Cookie
This single cookie recipe is a breeze to make! Beat the egg, butter, sugars, and vanilla until smooth and slightly fluffed, then add in the dry ingredients.
Roll dough in your hands to create a ball and then flatten about halfway or so that the mound is about 1 1/2 inches thick. Wrap it in plastic wrap, then chill for two hours.
Once the dough has chilled, bake until the edges have set and the top is just set, even if slightly undercooked, pale, and glossy in the center.
Do I Have to Chill Cookie Dough?
Yes! With all cookie baking, I recommend chilling the dough because the finished product will bake up thicker and be less prone to spreading from a little chill time, even if it’s just a flash-chill in the freezer for 30 minutes. I tried baking this cookie without chilling the dough and the results was nowhere near as thick.
Can I Use Instant Oats?
No, make sure to use old-fashioned whole-rolled oats. Quick-cook oats act more like flour and will not work here.

Tips for Making a Single Serving Cookie
Note that you only need one egg yolk for this big chocolate chip cookie, not the whole egg. Save the egg white for another use or discard.
I’m sure you could adjust this recipe slightly to make a small batch of oatmeal chocolate chip cookies. The ingredients would be the same, but instead of forming one giant cookie you’d need to form three or four.
If desired, you could shape and freeze the cookie dough and bake it off later. You’d want to bake the dough from frozen and add a couple minutes to the cook time.

Ingredients
- ▢ 1 egg yolk from a large egg , discard white or save for another use
- ▢ 2 tablespoons unsalted butter , very soft
- ▢ 2 tablespoons granulated sugar
- ▢ 2 tablespoons light brown sugar , packed
- ▢ ½ teaspoon vanilla extract
- ▢ ⅓ cup old-fashioned whole-rolled oats , do not use instant or quick-cook oats
- ▢ ⅓ cup all-purpose flour
- ▢ ½ teaspoon baking soda
- ▢ ½ teaspoon cornstarch
- ▢ ¼ teaspoon kosher salt , or to taste
- ▢ ⅓ cup semi-sweet chocolate chips , plus more for adding on top before and after baking if desired (recommended)
Instructions
- To a large bowl, add the egg, butter, sugars, vanilla, and mix with a spoon aggressively for about 90 seconds, or until smooth and slightly fluffed, i.e. your bicep and shoulder should be burning if you’ve mixed well enough.
- Add the oats, flour, baking soda, cornstarch (keeps cookie extra soft), salt, and stir to combine.
- Add the chocolate chips and stir to combine.
- Roll dough in your hands to create a ball and then flatten about halfway or so that the mound is about 1 1/2 inches thick.
- I recommend chilling the dough, wrapped in plastic wrap, in the fridge for at least 2 hours to ensure the cookie stays thicker cookie and spreads less. If desired, add additional chocolate chips to the top of cookie (recommended).
- Preheat oven to 350F, line a baking sheet with a Silpat or spray with cooking spray and place the cookie dough on it.
- Bake for about 12 to 15 minutes (shorter for softer cookies, longer for more well-done cookies), or until edges have set and top is just set, even if slightly undercooked, pale, and glossy in the center; don’t overbake. Cookie firms up it cools. Exact baking time will depend on how thick your dough mound is and how well-chilled it is going into the oven.
- Remove baking sheet from oven, top cookie with additional chocolate chips as desired (recommended), and allow cookie to cool on baking sheet until serving. Cookie is best warm and fresh.
Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
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One-Bowl, No-Mixer, Extra-Large Oatmeal Chocolate Chip Cookie
Ingredients
- 1 egg yolk from a large egg discard white or save for another use
- 2 tablespoons unsalted butter very soft
- 2 tablespoons granulated sugar
- 2 tablespoons light brown sugar packed
- ½ teaspoon vanilla extract
- ⅓ cup old-fashioned whole-rolled oats do not use instant or quick-cook oats
- ⅓ cup all-purpose flour
- ½ teaspoon baking soda
- ½ teaspoon cornstarch
- ¼ teaspoon kosher salt or to taste
- ⅓ cup semi-sweet chocolate chips plus more for adding on top before and after baking if desired (recommended)
Instructions
- To a large bowl, add the egg, butter, sugars, vanilla, and mix with a spoon aggressively for about 90 seconds, or until smooth and slightly fluffed, i.e. your bicep and shoulder should be burning if you’ve mixed well enough.
- Add the oats, flour, baking soda, cornstarch (keeps cookie extra soft), salt, and stir to combine.
- Add the chocolate chips and stir to combine.
- Roll dough in your hands to create a ball and then flatten about halfway or so that the mound is about 1 1/2 inches thick.
- I recommend chilling the dough, wrapped in plastic wrap, in the fridge for at least 2 hours to ensure the cookie stays thicker cookie and spreads less. If desired, add additional chocolate chips to the top of cookie (recommended).
- Preheat oven to 350F, line a baking sheet with a Silpat or spray with cooking spray and place the cookie dough on it.
- Bake for about 12 to 15 minutes (shorter for softer cookies, longer for more well-done cookies), or until edges have set and top is just set, even if slightly undercooked, pale, and glossy in the center; don’t overbake. Cookie firms up it cools. Exact baking time will depend on how thick your dough mound is and how well-chilled it is going into the oven.
- Remove baking sheet from oven, top cookie with additional chocolate chips as desired (recommended), and allow cookie to cool on baking sheet until serving. Cookie is best warm and fresh.
Notes
Nutrition
One-Bowl, No-Mixer, Extra-Large Oatmeal Chocolate Chip Cookie - AverieCooks.com