These unconventional overnight oatmeal cookies will shatter your “good cookie” rules. They are full of balanced sweet flavor, but challenge the notion of textural perfection. They bake up very soft and just lightly chewy in the middle, like classic oatmeal cookies. But they lightly spread, creating a chewier sweet edge. This might seem like a flaw at first, but it’s an addictive bonus in my opinion. Not to mention, you’ll love how easy this flourless recipe is to make!
Mama’s Overnight Oatmeal Cookies are Fabulously Butterless and Flourless
This recipe was originally shared by Sarah – it’s one of her family favorites. But I made a little tweak to the recipe, added information, and expanded the directions with more detail. So it’s become a team effort! I also took some photos, and have answers to some common questions for these overnight oatmeal cookies.
Overnight Oatmeal Cookies FAQ
- Can You Use Rolled Oats? Stick with quick oats. They are just as nutritious, but are sliced thinner than rolled oats. This allows them to more readily soak up the oil and sugar, producing a more tender cookie.
- Do I Have to Leave the Oats Overnight? We recommend it. While sitting, the oats absorb much of the oil and sugar, to help make a more cohesive cookie when baked. If you want to bake in the evening, just stir together the oat mixture in the morning. You can even mix it up a whole day in advance. I’ve forgotten the oat mixture on my counter before – it’s fine!
- Should I Grease the Baking Sheets? No. Grease will cause these overnight oatmeal cookies to spread more. Using parchment paper instead helps to absorb some moisture so they spread, but not too much.
- Can I Substitute the Eggs? I don’t recommend it. Because this recipe is “flourless” and chunky, eggs are the primary binder. If you need egg-free oatmeal cookies, try my Allergy-Friendly Oatmeal Cookies (also gluten-free) or Hannah’s Bakery-Style Vegan Oatmeal Cookies.
- Is this a Good Recipe for Kids? It’s great for getting kids into baking! Even little kids can help with measuring, mixing (done by hand), and putting the dough on the baking sheets. Older kids and teens who use the oven, can make these on their own.
- Why is the Dough So Crumbly? This is a flourless recipe. Don’t worry, it binds together as it bakes! Just dampen your hands (it’s sticky!) and press any loose bits back into the mounds of dough before baking. You can alternatively press the dough into muffin cups (use a piece of parchment to press to prevent sticking) if you want more even cookies.
- Can I Add Cinnamon? By all means! If you like a little spice, add 1 to 2 teaspoons of cinnamon when you mix up the initial oat mixture. Another option is to add a couple teaspoons of pumpkin pie spice.
- Can I Add Chocolate Chips or Raisins? This gets a little trickier. Since the dough is quite crumbly to start, it can get more difficult to handle if you add more chunky items. Mini chocolate chips will work best, but instead, I recommend Sarah’s chocolate dip suggestion in the recipe notes.
Special Diet Notes: Overnight Oatmeal Cookies
By ingredients, this recipe is dairy-free / non-dairy, gluten-free, nut-free, peanut-free, soy-free, and vegetarian.
- 4 cups quick oats (use certified gluten-free oats, if needed)
- 1½ cups light brown sugar, packed
- 1 cup oil
- 2 eggs, beaten
- 1 teaspoon vanilla extract
- 1 teaspoon salt
- The night before you bake, thoroughly stir together the oats, brown sugar, and oil in a large bowl. They should start to come together like a clumpy dough.
- Cover the oat mixture and let sit at room temperature overnight (or longer if needed).
- The next day, when ready to bake, preheat your oven to 325ºF and line baking sheets with parchment paper.
- In a medium bowl, whisk together the eggs, vanilla, and salt until beaten and combined.
- Pour the egg mixture into your oat mixture and stir until combined.
- Drop the dough by the level tablespoonful onto your prepared baking sheets a few inches apart. This is a very loose, crumbly dough. If needed, wet your hands to shape the dough and press it together. But leave the dough as mounds - don't flatten them. The cookies do spread on the edges as they bake.
- Bake the cookies for 15 minutes.
- Let the cookies cool on the baking sheets for 2 minutes, before removing them to a wire rack to cool completely.
- Store the cookies in an airtight container at room temperature for a few days. Freeze the cookies for longer storage.
Csn I usr old fashion oats?
They will be chewier with old fashioned oats, and might be little greasy / spread too much since old-fashioned don’t asborb as readily.
How many cookies does it make?
About 3 to 4 dozen
These were so easy & delish! Combined it with a smoothie and enjoyed for breakfast. I cut half the sweetener, and added a lil’ pumpkin pie spice. 🙂
That’s awesome! Thank you for your feedback Jenn.
Great idea to soak oats overnight! I think I’ll throw in a little pumpkin pie spice too 🙂
Ooh, pumpkin spice would be a nice touch Jenn!
We have made a similar recipe as part of our annual Christmas cookies for as long as I can remember. They are simple yet delicious. I usually add a bit of lemon zest with the oats/oil/sugar mixture.
My “dough” isn’t dough at all. Its more of a wet oat mixture. Nothing dough-y about it. Also you don’t specify to leave oat/oil/brown sugar mixture on counter or in fridge overnight
Yes, this flour-less batter is indeed a loose oatmeal mixture rather than a sticky ‘dough.’
Perfect for drop cookies!
I usually leave the overnight mixture out on the counter as I find the oats absorb the oil better that way, but refrigerating it is fine too.
Kimberly, also make sure you are using “quick” oats – not whole or rolled oats.
Is there any way to make this recipe without the eggs?
Karen, there is always a way! Though it may require some experimentation. You could use egg replacer, flax “eggs,” or 1/3 to 1/2 cup applesauce or mashed banana in place of the egg. Some other adjustments may be needed though. I find that oil-based, egg-free baked goodies often need the oil reduced a bit.
What is the calorie count on these?
I’m going dairy free for my little sweet pea’s benefit, but still crave delicious sweets…thanks for a great cookie recipe! Usually I sub applesauce for oil to make it healthier. Have you tried this, or do you think it would work out – to mix it and let it soak out overnight with the oats?
Liz, replacing all of the fat with oil typically makes cookies gummy. If this is something you are used to and like though, then it might work fine for you. Personally, if I wanted to lower the fat the most I would sub would be 1/2 to 2/3 of the oil. Keep in mind that applesauce will also change the texture.
I’d eat these for breakfast for sure!
So, flax eggs work, however the cookies spread and become one big thin cookie. Made the second batch by putting them in a cup cake pan to control the spreading and they turned out rather nicely. My little boy thinks they are a winner!
Fabulous idea Rebecca. Glad the egg-free veresion worked well that way, and thanks for the feedback!
Oh, I must try these for Mr. GFE who is a fanatic for all oatmeal cookies. 🙂 I’ll use another oil but I’m sure they will be great no matter what. 🙂
Thanks – i figured it was something like that. I tend to be a little impatient with things so understanding the “why’s” helps me be more patient 🙂
I hear ya! I don’t like waiting for dessert either 🙂
What is the purpose behind mixing some of the ingredients the night before? BTW – thanks for posting this recipes. Our family has milk allergies and gluten issues so finding tasty treats like this is very nice.
Hi David – Since you are using just oats, no flours, the resting time allows the oats to release some starches and soften before baking. It makes for a more cohesive cookie.
Could you use coconut oil instead of canola?
Definitely! Your favorite baking oil should work well, including melted coconut oil.
Love the simplicity of this recipe – it is so rare to see so few ingredients!