Looking for an easy gluten-free breakfast or snack to make in minutes? Whip up this fluffy oatmeal cake in a mug with no flour required, only oats! Using my simple hack, stirring halfway through, means a light, fluffy, yet moist, texture every time! Oat mug cakes use simple ingredients, right in your kitchen, so you can enjoy this treat right now, in only 2 minutes!
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Game-Changing Oat Cake In a Mug
Why am I oatmeal’s biggest cheerleader?? If you are on a gluten-free diet (and can tolerate GF oats), using oatmeal or oat flour is a game changer. It’s affordable, tasty, and won’t cause you any GF drama! Making a mug cake with oatmeal helps build structure, acts as a binder, and 100% oat recipes require no flour!
To make this oatmeal mug cake just grab some GF oats, milk, egg, maple syrup (or brown sugar), oil, and baking powder. You’re equipped with those, right? So enjoy it whenever the fancy strikes. And, like a fudgy chocolate almond flour mug cake, it can easily be modified for dairy-free or sugar-free.
A flourless oatmeal mug cake not only hits when the sweet tooth strikes, but can objectively be considered hearty enough for an easy gluten-free breakfast idea. Want to go all out? Instead of topping with chocolate chips, pile on whipped cream, ice cream, a scoop of peanut butter, chopped nuts, or fresh berries.
Although this recipe doesn’t require any immense cooking / baking skills, just a desire, below I touch on workable ingredient swaps, tips for preventing a rubbery cake, topping ideas, along with many easy tips to make a perfectly fluffy oat cake in a mug every time!
This👏🏼is👏🏼SO👏🏼delicious! Can’t even lie, I make this every other night and I have no regrets😏😋😏
—Erica
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Ingredient Tips and Subs
- Egg – Using one whole egg best mimics the texture of cake. For an egg-free option replace with 1/2 mashed banana. I found when try this, though, the texture was more like baked oatmeal than cake.
- Oil – Also ideal for a fluffy cake texture, but any preferred oil may be used, such as canola or melted coconut oil. You can also swap out an equal amount of creamy peanut butter, but it will have a slightly more dense texture.
- Sweetener – When testing the recipe I found pure maple syrup made for the best results. Brown sugar or coconut sugar will also work, but dries out texture slightly. If making this for breakfast or a light dessert, you may also reduce the sweetener. I have not tried this recipe with a sugar-free substitute, but I see no reason why it wouldn’t work as well.
- Oats – Use quick-cooking oats or oat flour for best results. You can use dld fashioned rolled oats, but the crumb will be heavier and more rustic. For a GF recipe, be sure to use certified gluten-free oats.
- Milk – For a dairy-free recipe, replace with soy, oat milk, almond milk, or any preferred non-dairy substitute. No issues there at all!
- Chocolate chips – Optional, but why not?! Using miniature chocolate chips stays more evenly dispersed throughout the batter. You may also leave them out for a dairy-free version.
Let’s Make This Together!
(Below shows step-by-step photos and modified instructions. For the complete recipe, along with ingredient amounts, scroll down to the recipe card.)
Whisk wet ingredients
Key point here is make sure your mug or ramekin is at least 10 ounces or else your 2 minute project will turn into a longer clean up mission. Spray it with nonstick cooking spray and use a fork to whisk together the egg, maple syrup, oil, milk, and vanilla extract.
Stir in dry and magic cooking tip
Now stir in your dry ingredients – oats, baking powder, cinnamon, and salt. If you’re using chocolate chips, do not add them yet or they will get all melty. But go for it if you are looking for a chocolate oat version. Ready for the magic? Cook for 45 seconds at full power. Remove and stir again. This helps the egg disperse, not settle to the bottom, and avoids rubbery results. Then return to the microwave for 45-60 seconds more. Wait long enough to not burn your mouth (or not) and enjoy!
Recommended Oats or Using Oat Flour
Since oat mug cakes have a short cooking time, it’s essential to use fine, smaller, quick-cooking oatmeal for the fluffiest results. Quick oats absorb the liquids better in the short cooking time.
Another option would be to substitute an equal amount of oat flour. An oat flour mug cake would have an even more cake-like texture, so if you have it on hand, give it a try!
If you don’t have any in your kitchen, you can still easily make it in seconds, though. Place ½ cup quick or rolled oats in a blender. Blend for 30-45 seconds, or until no large flakes appear. Voila! Replace for the oats to make an oat flour mug cake in minutes!
How To Avoid Rubbery Mug Cakes
Most mug cake recipes require an egg, which can become rubbery when cooked in the microwave. So how can we avoid this unpleasant texture in an oatmeal mug cake?
Easy! To avoid a rubbery cake, use a fork and stir the batter halfway through cooking. This will evenly distribute the egg throughout and absorb into the other ingredients. Also, be sure to not overcook, which causes too much moisture to evaporate.
Seriously Delish Toppings
It’s best enjoyed warm, and frankly as is works great, but it’s hard to not dream up some tasty toppings. For a next level decadent dessert, dollop a scoop of ice cream, whipped cream or event hot fudge on top.
If making this for breakfast or a lighter dessert, I usually go for fresh berries, nuts, coconut, sliced bananas, or even a scoop of peanut butter.
While the single serving size helps portion control, it can easily be divided into two servings, especially when adding toppings. But if you’re looking to super-size your dessert (who isn’t?!) this 5-minute blender oat flour cake with brown sugar frosting checks all the boxes!
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Did you make this recipe? I love hearing from you! Leave a star rating and comment below the recipe card. It helps others when searching for recipes and I appreciate feedback from our community. You will always hear back from me! -Melissa
2 Minute Oatmeal Mug Cake (Fluffy, No Flour)
Ingredients
- 1 large egg
- 3 tablespoons milk, or dairy-free alternative
- 2 tablespoons pure maple syrup, preferred, see recipe notes for subs
- 1 tablespoon oil, canola, vegetable, or melted coconut oil
- ½ teaspoon vanilla extract
- ½ cup quick-cooking oats, certified gluten-free for GF cake
- ½ teaspoon baking powder
- ¼ teaspoon ground cinnamon
- ⅛ teaspoon salt
- ½ tablespoon miniature chocolate chips, optional
Instructions
- Grease a 10 ounce microwave-safe mug or ramekin with nonstick cooking spray. Use a fork to whisk together egg, milk, maple syrup, oil, and vanilla extract.1 large egg, 3 tablespoons milk, 2 tablespoons pure maple syrup, 1 tablespoon oil, ½ teaspoon vanilla extract
- Using the fork, stir in the oats, baking powder, cinnamon, and salt. If using chocolate chips, do not add them yet.½ cup quick-cooking oats, ½ teaspoon baking powder, ¼ teaspoon ground cinnamon, ⅛ teaspoon salt
- Pour the batter into the prepared mug. Place in the microwave and cook for 45 seconds at full power. Remove and use a fork to stir the batter until uniformly mixed again. This helps the egg disperse, not settle to the bottom, and avoids rubbery results. If adding chocolate chips, add now and briefly stir to disperse.½ tablespoon miniature chocolate chips
- Return to the microwave and cook 45-60 seconds more. There will still be a little moisture at top, and that is fine. It will absorb as it sits for 1 minute before serving. Avoid over cooking for best texture.
Notes
Sweetener Options
Using pure maple syrup yields the best results. Brown sugar or coconut sugar will also work, but may dry out texture. You may also reduce the amount of sweetener to 1 or 1½ tablespoon. I have not tried this recipe with a sugar-free substitute, but I see no reason why it wouldn’t work as well.Helpful Tips to Remember
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I love this recipe. I usually 6x the recipe and bake it in ramekins in the oven at 350 degrees for 45ish minutes. I also changed out the butter for applesauce and only did 1 Tbs of maple syrup. And I blend up the oats to make it more cake like. Easy and nutritious breakfast!
Thank you for these wonderful ideas, Sondra! Sounds amazing.
Best,
Melissa
So quick and tasty! I used homemade oat flour (I make it in the blender like you suggest and I leave just a few whole oats for some texture). I didn’t bother to stir halfway through. Maybe because the oat flour makes for a thicker mixture, it didn’t seem like anything was settling. I didn’t end up adding chocolate chips since I skipped the stirring step. It came out delicious, cake-like but healthy and filling. I’ll definitely do it again and plan to add chocolate chips right at the beginning next time. Thanks for sharing this! (I wonder if some of the people with bad outcomes are using rolled oats instead of quick, I can imagine that wouldn’t work well.)
Thank you for all your helpful notes, Julia. I’m so glad you enjoyed the recipe!
Best,
Melissa
Turned out great! Next time I’ll sub some liquid stevia for part of the maple syrup. Maybe add the jnut butter too.
Lovely to hear, let me know how that turns out for you!
Best,
Melissa
This was quick, easy, delicious 😋. I added 6 dark chocolate chips. Next time I’ll cut back the maple syrup to 1 T and add some liquid stevia. The nut butter sub for oil is a good idea too!
Fell apart was really just carmelized oats.
Sorry to hear that, Bee, I’m not really sure what happened here 🙁
Best,
Melissa
FABULOUS!! Moist, flavorful and filling!!!
Oh, yay! Thanks for letting me know! I love that 🙂
Best,
Melissa
My first try ended up more like a custard—Not quite what I was craving.
My second attempt I made one tiny change to make this more like a gooey cookie texture: use only the egg yolk, and sub in a splash more milk in its place. It turned out gooey and amazing!
Thanks for the tip, Thomas. I’m so glad you were able to rectify it and make it a success. I appreciate you taking the time to write!
Best,
Melissa
This was an epic fail for me 😂 My mix came out too thick/solif. When I removed it from the microwave to stir halfway, I ended up with a sort of scramble 😬 By the end I just had a crumbled sticky thing lol. Still ate it, and it was tasty at least 🙂
Oh no! I admire your commitment to not throwing food away. I would have been right there will you! 🙂 If it was that thick maybe some the liquid wasn’t added or too many oats? I’m not sure why it would have come out like this, but regardless, I’m sorry. Kitchen failures are never fun.
Best,
Melissa
I am eating my first try now and it’s great. I used blueberries instead of chocolate chips. Molasses instead of maple syrup. Will make again.
Thank you, Rita! That sounds wonderful and I bet the hint of molasses adds a great taste!
Best,
Melissa
I’ve made this twice in two days! The first time I made it as written (minus the chocolate chips) with standard (not rolled or jumbo) porridge oats – perfect fluffy muffin. Today I substituted a mashed banana for the maple syrup and a heaped tablespoon of smooth peanut butter for the oil. Added a tbsp of 70% dark chocolate chips. It’s not as fluffy or cake-like as the original recipe (more liked baked oats) but it’s still very good.
PS replying to my own message to add that it is a bit softer in the middle this way and I don’t think it would work in a mug. I used a 0.7 litre pudding basin which was fine, but I’m going to try using a flatter/wider square dish tomorrow.
Good tip! Appreciate it, Katy!
Best,
Melissa
Oh, thank you so much for sharing! Yes, I can imagine the banana would give it more of a baked oatmeal texture, but still sounds delish!
Best,
Melissa
I made this for breakfast today but what I did was blend it all up so it was smooth. I did use peanut butter which did make it a bit more dense but still semi fluffy. I added chocolate chips at the end. I thought it came out really good. I would make it again the same way.
Love this tips, Susan! Thanks for taking the time to share!
Best,
Melissa
If i wanted to add a banana to this recipe, would you recommend I swap it with one of the other ingredients?
Hi Michele,
I haven’t tested this, but I would say your best bet is to chop up half a banana and add it with the other ingredients. It will probably have to cook a little longer and be sure to your cooking container is a little larger so it doesn’t spill over. Let me know how it goes!
Best,
Melissa
Thank you! I tried the original recipe last night And it was excellent! I’ll try it with banana next!
Thanks Michele! Let me know how it goes with the banana!
Best,
Melissa
This was really good. I think it needed several minutes to cool, but it was well worth the wait.
Thanks so much! Glad you enjoyed it!
Best,
Melissa
The recipe did not work. It was liquidly and never bonded up. I let it sit, I even put it in for a little bit longer. I followed the directions exactly how they are stated and used the appropriate wattage microwave. It was horrible. It was loose and just not good at all
I’m really sorry to hear this, Rose. I wish I could figure out what happened. What kind of oats did you use? I know how frustrating it is for recipes to not turn out 🙁
Best,
Melissa
This👏🏼is👏🏼SO👏🏼delicious! Can’t even lie, I make this every other night and I have no regrets😏😋😏
Nothing makes me happier to hear! Thanks Erica!
Best,
Melissa
This was excellent, I added a few white chocolate chips instead and little low fat caramel was really good.
Thanks Corrine! I appreciate it!
Best,
Melissa
I’m sorry but this was nasty as….heck. I don’t know how these people are rating it 5 stars. I made it exactly as instructed, I’m not new to the kitchen. Same ingredients same measurements, (Even same microwave wattage 😉) did the midway stir, followed to a T. I took it out of the microwave and it was jiggly and very visibly ‘moist.’ Okay recipe says don’t worry it will setup. I waited over a minute and still did not absorb. Okay tried to put it in the microwave a bit longer, nope. I even dumped the wet jiggly mess out of the mug into a rectangle ramen dish and spread it out to try to help it cook or at least do SOMETHING. Nada. Not only did it just turn into a gross jiggly wet mess, it has pretty much no flavor. I had my teenage daughter make this too so I could see if it was just me and hers came out about the same way. Sorry,…but if you want an oatmeal mug cake….this ain’t it 🤷🏻♀
Update: Also tried with Old Fashioned Oats since that would result in a drier texture and it was still a gelatinous blob of ick.
Hi Dez,
I’m not really sure how to respond to this because I’m not sure what happened. I’ve made this recipe a lot and it’s very popular on the site, as well as across Pinterest. I’m sorry it didn’t work out for you. That’s never fun and I can understand why you would be frustrated.
Best,
Melissa
Hi. I love your oatmeal mug muffin. I make it for breakfast 2-3 times per week! Yum!! Thanks for sharing!
Jolayne
Thank you, Jolayne! I’m right there with you. I have a sweet tooth in the morning and always have yogurt parfaits or oatmeal. This sounds like a great way to start the morning!
Best,
Melissa
Delish! I substituted almond butter instead of oil and it came out amazing! Topped it with some Greek yogurt and it was a great sweet treat! Would definitely make again and glad I stumbled upon this recipe 🙂
Yum, what a tasty substitute! Thanks for sharing!
Best,
Melissa
I love oatmeal and I love mug cakes. When I made this I only had Old Fashioned Oatmeal, I also substituted olive oil. I didn’t have chocolate chips. It came out fine. I’m sure the texture would be different with the right kind of Oatmeal, but the flavor was good. I topped it with Greek yogurt and nuts. I make it again.
Thanks for sharing, Peggy. Yes, you can use old fashioned oats, it just wouldn’t bind as much, maybe more like a baked oatmeal consistency. Thanks for taking the time to write!
Best,
Melissa
I cook for one which is often a challenge, so I’m so glad to have tried this. I found it is very flexible and forgiving when it comes to substitutions and slight changes. I used brown sugar instead of maple syrup per your suggestion, and added a touch more milk so it wouldn’t be dry. I had no oil, so I melted some butter and stirred the first ingredients into that, poured it into the greased mug, and added the other ingredients. The result had a consistency half way between a coffee cake and a dense bread pudding, both of which I love, so I greatly enjoyed it, even without the chocolate chips.. I will be making this again for sure .
Thank you, David! Your comment means a lot and I appreciate you taking the time to let me know!
Best,
Melissa
Made this for lunch today. I used part oatmealflour and oatflakes. Put in some chocolatechips and red fruit. You definitely need to use a big mug because it rises really good! Was sooo good!
Thank you, Miranda! That sounds like a lovely lunch!
Best,
Melissa
Can you make this recipe with an oven. I’m weird and don’t have a microwave. Thanks
Totally understand. Place the batter in a greased oven-safe mug or ramekin. Bake at 350 for 12-15 minutes, or until a toothpick comes clean. You won’t have to worry about mixing it halfway through since the oven will bake it more gradually. Hope this helps!
Best,
Melissa
Thanks for this recipe! I was looking for a healthier mug cake. It’s very filling and satisfying. I would recommend a larger than 10 oz mug, which overflowed. Other than that, it came out great. I’ve been substituting molasses for the maple syrup and that also comes out well.
Thanks Mary!
I tested in a 10 ounce ramekin, so I wondering if the shape of a mug versus ramekin had anything to do with it. Sorry for the mess, but glad you enjoyed it!
Best,
Melissa
Great for an easy sweet treat/breakfast with at the house ingredients! Will definitely make again!
Thanks, Levi! I’m so glad you love the recipe!
Best,
Melissa
Great snack. I even put in less than 1 TBSP maple syrup and less chocolate chips. Would definitely recommend and make again.
Thanks, Wendy! I appreciate it!
Best,
Melissa
I think this recipe needs a lot of individual tweaking as the final product depends a lot on the wattage of your microwave, the size of the egg, how finely the oatmeal is ground. The taste is good, but I followed the recipe exactly and mine turned out too dry. The longer it sits the drier it gets. Maybe a good idea to add more milk at the end?
Hi Teresa,
You are right the wattage of the microwave will make a difference, just like in any recipe with microwave directions. Since I only have the one in my kitchen to test recipes, I can’t explicitly say how different wattage microwaves will adjust the baking time. If it helps, mine is a 1000 watt oven so you can make adjustments from there. I’m curious about the oats. Did you use oat flour or quick oats? Generally quick oats are a pretty uniform size, but yes oat flour can be different consistencies, especially if you are grinding it at home. Adding a little more milk would help offset a dry texture.
Best,
Melissa
I only had oat flour, so I used a tiny bit less than called for and this was great. A bit more than one serving for me, but very tasty and quick. Genius tip to stir it. I wasn’t sure it would work since it had started solidifying, but it came out so uniformly soft and cakey!
Thanks, Angie! Yes, when I make this I can’t eat it in one serving either, but at least you don’t have a whole cake sitting around tempting you! Glad you enjoyed the tip.
Best,
Melissa
Can you use old fashioned oats? It’s all I have.
Hi Tracy, Yes, you can. The texture will just be a little different, a little more rustic, not quite as fluffy, but the taste will still be good!
Best,
Melissa
I made this for breakfast today. It was delicious! I used milk chocolate chips, more than half a tablespoon, because I’ll be 70 next month and I felt like it. And I think more chocolate helps make up for having to eat gluten free. Except for that, I followed your recipe exactly. Thanks for sharing your yummy recipes, I have made several of them and all have been delicious.
Thanks Joansy! I agree about the chocolate factor. I typically don’t measure chocolate because how can a little more ever hurt??
Best,
Melissa