Whether you think of this as a healthy oat flour mug cake or a single-serving muffin, either way it's delicious! This oatmeal mug cake is fluffy, tender, just sweet enough, and perfect any time of day. Try it with cinnamon for cinnamon roll vibes or pumpkin spice for a festive treat!
This recipe is free from oil, dairy, gluten, soy, coconut, and refined sugar.
Well, I'm at it again with the oat flour. I really can't explain it, but somehow, every time I start experimenting with some sort of baked goods recipe, I just get the most amazing results with oat flour.
Whole wheat flour can sometimes taste a little too "whole-wheat-y" if you know what I mean. And all-purpose can sometimes lean toward gummy when baking without oil (unless you start expanding the ingredient list and making things more complicated).
But I'm a fan of simple. And the flavor, fluff, and forgiving texture of oat flour just works. For that reason I highly recommend you stick with oat flour for this recipe if possible.
Also, I have to say, these photos really aren't doing this mug cake justice. You may not be able to tell, but it's very tender, light, and fluffy.
And true to its name, it's as easy as any mug cake! Although, for the best results I do recommend mixing wet ingredients in one mug and dry ingredients in a separate mug, just to make sure there are no clumps and that everything is well distributed.
But after that, just pop this baby in the microwave, press a few buttons, and watch it rise!
RELATED: Love quick and easy mug treats? Try this 5-Minute Microwave Granola!
Instructions
- In a standard, 10-ounce, microwave-safe mug (a larger mug is fine, too), combine the nut butter, milk, maple syrup, and vanilla. Stir really well until it resembles the mixture in the photo above (though the color may be different depending on nut butter used).
- In a separate mug, stir together the oat flour, baking powder, salt, and pumpkin spice or cinnamon.
- Pour the dry ingredients into the wet ingredients, and stir until there's no dry flour.
- Note: my microwave is 1100 watts. Microwave ovens vary. So stay nearby and keep an eye on the mug the first time you try the recipe. Mine come out perfectly when cooked for 70 seconds on high. BUT I recommend starting with just 50 seconds to be on the safe side. Then microwave for another 10 to 20, depending on how much it's rising and whether the center appears firm. If using a smaller, lower wattage microwave you may need to add more time. Do this in 10 to 15 second intervals.
- Let the mug cake rest for 5 minutes before serving.
Haha, "serving." Who are we kidding? We're not serving this to anyone but our own hungry faces.
Can I bake it?
Yes, if you prefer not to use the microwave, you can bake the mug cake in a 350 degree oven for around 15 to 18 minutes. Make sure your mug is oven-safe.
And since this is essentially a muffin batter, I'm sure you can also bake this the same way you might normally bake oil-free muffins - whether you use a silicone pan, or cupcake liners.
I haven't tested it in a muffin pan yet, but it should bake faster than in a mug. So keep a close eye on it in the last few minutes just to be safe.
Substitutions
With such a small, specific recipe like this, even tiny adjustments can make or break it. So while I would love to be able to say you can sub any flour you like, etc, I really can't say that with confidence.
Each ingredient has a purpose, including the maple syrup and nut butter. Though you may use any nut or seed butter you like, so at least there is some flexibility there!
I tested the recipe once using ¼ cup of King Arthur's gluten-free 1:1 blend, and I'm sorry to have to report, it really wasn't good. It cooked up properly and was edible, but the overall flavor needed some adjustments.
So if you want to go that route, I recommend experimenting with a bit more maple syrup and spice.
Serving Suggestions
For breakfast or a snack, a few spoonfuls of creamy non-dairy yogurt pair perfectly with this oat mug cake.
Or if you're in the mood for dessert, pair it with Vanilla or Pumpkin Oat Ice Cream, extra maple syrup, or some healthy Chocolate Sauce!
I hope you love this healthy mug cake as much as we do. It's:
- naturally sweetened
- light and fluffy
- made with just 7 simple ingredients
- comforting and spiced like your favorite fall and winter treats
- gluten-free (be sure to use certified GF oats/oat flour)
- oil-free
- ready in minutes
- and healthy enough for breakfast!
More oat flour recipes:
Lemon Poppy Seed Muffins
Cherry-Pistachio Muffins
Oat Flour Pancakes
Lemon-Blueberry Pancakes
Oat Flour Banana Bread
Apple-Cinnamon Oat Flour Scones
Oil-Free Vegan Chocolate Cake
Peanut Butter Cookies
Healthy Oat Mug Cake (Oil Free)
Ingredients
Wet ingredients:
- 1 very full tablespoon smooth nut butter such as almond, cashew, or peanut butter - Sub seed butter if needed.
- 2 tablespoons non-dairy milk, such as unsweetened almond or oat milk
- 2 tablespoons maple syrup
- ½ teaspoon vanilla extract, optional
Dry ingredients:
- ⅓ cup fine oat flour (34 grams)
- ½ teaspoon pumpkin spice blend or cinnamon
- ½ teaspoon baking powder
- pinch of sea salt
Instructions
- In a standard, 10-ounce, microwave-safe mug (a larger mug is fine, too), combine the nut butter, milk, maple syrup, and vanilla. Stir well so that the nut butter is fully incorporated.
- In a separate mug, stir together the oat flour, baking powder, salt, and pumpkin spice or cinnamon. Pour the dry ingredients into the mug with the wet ingredients, and stir until there's no visible dry flour.
- Note: this recipe was tested in an 1100 watt microwave. Microwave ovens vary, so stay nearby and keep an eye on the mug the first time you try the recipe. Begin by microwaving on high power for 50 seconds. Then microwave for another 10 to 20 seconds, depending on how much the cake has risen and whether the center appears firm. In my microwave, this recipe comes out just right with a cook time of 70 seconds. If using a smaller, older, or lower wattage microwave you may need to add more time (do this in 10 to 15 second intervals.)
- Let sit 5 minutes, then enjoy! For breakfast it's delicious with plain vegan yogurt and a sprinkle of hemp seeds. Or if enjoying as a dessert, try it with your favorite vegan ice cream, dairy-free whipped cream, and/or maple syrup.
Notes
Tips
If you don't have a kitchen scale, I recommend fluffing up the oat flour with a whisk or fork before measuring. A smooth, glazed ceramic mug works best for mug cake, allowing the cake to rise well, as opposed to a rough or bumpy surface (like pottery or unglazed ceramic).Baking Instructions
If you prefer not to use a microwave, you can bake the mug cake in a 350 degree oven for around 15 to 18 minutes. Make sure your mug is oven-safe. Test for doneness by lightly pressing the top, which shouldn't be wet, or inserting a toothpick which should come out dry. And since this is essentially a muffin batter, you can probably bake this the same way you might normally bake oil-free muffins - whether you use a silicone pan or cupcake liners. *I haven't actually tested it in a muffin pan yet, but it should bake faster than in a mug. So keep a close eye on it in the last few minutes just to be safe.Estimated Nutrition (per serving)
Nutrition information is an estimate and will vary depending on the exact amounts and specific products and ingredients used. We calculate this information using the online calculator cronometer.com.
Jen
Can u just use regular flour?
Lori
You can always experiment, but I think it would probably be better to use a mug cake recipe written specifically for regular all-purpose flour. With recipes like this (small amount, few ingredients), substitutions tend to make a pretty big difference.
Sofia M
This was SO GOOD!!!! I swapped quinoa flour for oat flour, and used 3 T milk and only 1 T of agave nectar (I had just ran out of maple syrup😢). It was a bit dense, but that kinda just made it even more awesome!
Thank you so much for this awesome recipe! 😀
Emily
It was super easy to put together, I did find it a bit dry. Maybe a different nut butter? (I used peanut butter) I used half the amount of maple syrup as I didn’t want it too sweet. I’ll try it a little different next time 🙂
Lori
Hi Emily,
Reducing the maple syrup would make it more dry. You could try a spoonful of applesauce next time, to replace the omitted maple syrup. That would help with moisture but not add noticeable sweetness.
Pam
I just made this and had the same issue.. i tried it with almond butter and swapped maple syrup with stevia powder. Just tried to cut down on the calories but i guess its the reason why it was crumbly. Less moisture. Will give it another try soon.
Also i made it in ramekin the and kept it in the air fryer at 180°C for 15mins.
Mia
Really hit the spot. Added a couple white chocolate chips in the middle. Yum.
HKS
This is great! I always get so excited for mug cakes/muffins that sound good and then am disappointed but NOT with this one! It's moist and delicious!
Sue Ivory
I just made this as a Thanksgiving weekend breakfast treat. I did not have oat flour but had fine oat bran, I used a heaped 1/4 cup as I also added two tablespoons of apple sauce! served with vanilla soya yoghurt, a drizzle of maple syrup and a shake of tiny vegan dark chocolate drops served with large vegan decaf mug of coffee. A delicious autumnal hug in a bowl in my Pj's.
sally
I tried this cake this morning and it was amazing, I love it 😋!!
Do you think it would taste good if I added Nutella next time instead of nut butter?
Lori
So glad you enjoyed it, Sally! Yes, I think Nutella will be delicious.
Sahasra
Can I skip the nut butter?
Lori
Unfortunately I don’t think that will work well. Having some fat is important for texture. You could experiment with applesauce, banana, or vegan yogurt, but I’m not sure how the results will be.
Oliver
This turned out so delicious! This cake is my go-to snack from now on 🙂
Dhyanitha
I tried this recipe exactly as you said. It took 2 minutes in my microwave to get done. It was soo delicious! Very yummy. My husband loved it very much :))
Lori
I'm happy to hear that! Thank you for taking a moment to let us know. 😀
Carly Green
This little mug recipe is great! I love PB and syrup from growing up and this hits all those sweet nostalgic notes all the while satisfying my sweet tooth with ZERO refined sugar!🤩 In love! Thank you so much for sharing!
Lori
I'm so happy you loved it, Carly. Thanks for sharing!
Olivia
Was craving cake so pleased to see this in my inbox! Mine only rose half way up the cup and was very dense. Suspecting I used too much almond butter. Will try again tomorrow. Tasty regardless!
Lori
Oh, good timing! Hmmm, I hope it rises better next time. Often when I haven't replaced my baking powder in a while that happens. But it might also be a difference in microwaves (did you microwave it?). Glad you like the flavor, Olivia! 😀
daisy
This looks like a luscious treat. I'm with you on the oats. After recently becoming sensitive to wheat, I've gone wild for oats! The oat flour works so well in so many recipes. I recently posted a pancake recipe using oats and they are fantastic.
Thank you for sharing the good stuff!
Lori
Oh hooray, glad I can help! Mmmmmm, I should do a pancake recipe soon.