A few days after I sent over the footage for this TV episode to my video editor, he sent me an email. He mentioned that while making a mug cake that evening for dessert, he remembered the super easy 3-ingredient chocolate drizzle I included in that episode, so he tried it on his mug cake…
And he called it magical! His kind note made my entire day, so I quickly typed out a response. Inside, I included that I had made a major mug cake break-through of my own when I started microwaving them on 30% power instead, and I shared an explanation of why that made a huge difference, along with my favorite mug cake recipes.
The following weekend, he sent me another email about how he tried my recipe and also made the same mug cake for his significant other and mom. He included a picture along with their reviews…
All three of them proclaimed my recipe as the best mug cake ever! My editor even went on to say it made his own mug cake recipe look like a sad pretender. I felt like I was on cloud nine for days—that’s such high praise!
So in honor of my incredible video editor, I’m sharing my favorite mug cake recipe with you: this Healthy Flourless Chocolate Mug Cake! It’s supremely rich and chocolaty, even with no eggs, butter, refined flour or sugar. And it’s just 108 calories!
True single-serving dessert perfection! 😉
Like I previously mentioned, I make my healthy mug cakes a little differently than most traditional recipes! Since my healthy mug cakes contain a lot less fat than typical recipes, I microwave them on 30% power instead for a longer period of time.
If you microwaved them on high for 1 minute like in traditional recipes, that would result in tough or gummy textures. However, this lower power better simulates baking in a regular oven, so your mug cakes turn out nice and tender instead!
So now with that nerdy microwave science out of the way… Let’s talk about the ingredients you’ll need!
First up is cocoa powder. Use the regular unsweetened kind, like this! Do not substituted Dutched or special dark cocoa powder. In this particular recipe, they actually have a much less prominent chocolaty flavor… Almost a little dull and bland. Regular unsweetened cocoa powder gives your healthy mug cake the most chocolaty and rich flavor!
I struggled with the name of this recipe… Should it be called “flourless” or “practically flourless” instead? That’s because you’ll mix in oat flour next, like this! (Or this for a gluten-free version!) Oat flour is simply finely ground oats so… I’m not sure if it technically counts as flour. I’ll let you decide!
Tip: You can make your own oat flour at home! I show you how here.
This low-calorie chocolate mug cake only requires ¼ teaspoon of coconut oil (or butter, if you prefer!) and no eggs. Instead, it gets the rest of its moist texture from Greek yogurt! I always love baking with Greek yogurt because it adds the same moisture to your batter as extra butter or oil for a fraction of the calories. And it gives your treats a protein boost, too!
You’ll skip the refined granulated sugar and sweeten your flourless chocolate mug cake with liquid stevia. It’s another one of my favorite ingredients! Stevia is a plant-based, no-calorie sweetener that contains nothing refined or artificial (aka it’s clean-eating friendly). It’s also really concentrated—you need less than ½ teaspoon for your healthy chocolate mug cake!
This is the liquid stevia that I use because I love its sweet flavor and don’t notice any strange aftertaste like with some other stevia products. You can find it at many health-oriented grocery stores, but I buy mine online here because that’s the best price I’ve found. (And you’ll use it in all of these recipes of mine, too!)
How decadent does that look?? There’s a reason I make this healthy flourless chocolate mug cake nearly every day! 😉 And with a certain holiday right around the corner… This would definitely make for a super easy (and healthy!) Valentine’s Day dessert!
And when you make your own, remember to snap a picture and share it on Instagram using #amyshealthybaking and tagging @amyshealthybaking IN the photo itself! (That guarantees I’ll see your picture! 🙂 ) I’d love to see your mug cake!

Healthy Flourless Chocolate Mug Cake
Ingredients
- 2 tbsp (15g) oat flour (gluten-free, if necessary, and measured like this)
- 2 tbsp (10g) unsweetened cocoa powder (measured like this)
- ⅛ tsp baking powder
- 1/16 tsp salt
- ¼ tsp unsalted butter or coconut oil, melted
- 1 tbsp (15g) plain nonfat Greek yogurt
- 5 tsp nonfat milk
- ¼ tsp vanilla extract
- ⅜ tsp liquid stevia (or adjusted to taste)
- optional: 1 tsp miniature chocolate chips (divided)
Instructions
- Lightly coat a 1-cup ramekin with nonstick cooking spray.
- In a small bowl, whisk together the oat flour, cocoa powder, baking powder, and salt. In a separate bowl, stir together the butter, Greek yogurt, and milk. (See Notes!) Stir in the vanilla extract and liquid stevia. Gradually mix in the flour mixture, about 1 tablespoon at a time, until just incorporated. If using, gently fold in ¾ teaspoon of chocolate chips.
- Spread the batter into the prepared ramekin, and gently press the remaining chocolate chips on top (if using). Microwave on 30% POWER for 2 minutes 40 seconds (2:40). Let the mug cake cool for at least 4 minutes to allow the center to finish cooking through.
Notes
View Nutrition Information + Weight Watchers Points
You may also like Amy’s other recipes…
♡ Healthy Triple Chocolate Mug Cake
♡ Healthy Mocha Chocolate Chip Mug Cake
♡ Healthy Chocolate Chip Mug Cake
♡ Healthy Snickerdoodle Mug Cake
♡ Healthy Peanut Butter Mug Cake
♡ Healthy Carrot Cake Mug Cake
♡ Healthy Vanilla Mug Cake
I don’t have that sweetener, so I used 1 bsp of coconut sugar, and it was too salty/bitter. I ate it, but it wasn’t a classic desert. I liked the consistency, and how easy it is to make, but next time I’ll use at least 2 tsp of coconut sugar.
I’m honored that you tried making my recipe Jana! As I mentioned in the Notes section of the recipe (located directly underneath the Instructions), the vanilla stevia is the equivalent of 2-3 tablespoons of sugar. (I know it can be easy to miss that section!) If you just used 1 teaspoon of coconut sugar, that’s why your mug cake was so bitter — that’s the equivalent of 1/6th to 1/9th of the amount of sweeter that the recipe calls for! 😉 Depending on how much you like dark chocolate, I’d definitely recommend using more than 2 teaspoons. That amount will probably make your mug cake taste like 90% dark chocolate. Does that make sense? 🙂
Yes, thank you 🙂
It’s my pleasure Jana! I’m always happy to help! 🙂
I tried making this and followed the recipe but the batter was incredibly thick, I actually had to add almost double the amount of milk in order to turn it back into a batter..after microwaving it didn’t really cook but turned into a kind of cooked dough? Not sure what went wrong but didn’t work for me at all.
I’m honored that you tried making my recipe, Devika! That sounds frustrating and not like how this mug cake is supposed to turn out at all, so I’d love to work with you to figure out what happened. 🙂
How did you measure the oat flour and cocoa powder? Did you use measuring spoons or a kitchen scale? If the former, did you happen to dip them directly into your containers of flour and cocoa powder?
You mentioned adding almost double the amount of milk — so you used a little more than 3 tablespoons in total, correct? How was the flavor — was it rich and chocolaty or on the bitter side? Finally, did you make any modifications to the recipe, besides using additional milk, including those listed in the Notes section?
Did you use 30% power, and do you happen to know the wattage of your microwave?
I know I just asked a LOT of questions, but once I know your answers to all of them, I should have a much better idea of the potential culprit and how to fix it!
Hi Amy!
Mine also turned out thick! I used heaping tablespoons of oat flour and cocoa powder, and then read at the end that it was very important to be exact about the measurements, so I’m thinking this was my mistake!! I added more milk until it turned into a batter, and am now having to play around with the cook time, but I’m very excited to see how mine turns out!
Hello!
This looks super yummy! Can i replace the chocolate with chocolate syrup?
Thank you so much!!
Is it ok to use almond milk?
I’ve actually covered this in the Notes section of the recipe (located directly underneath the Instructions!). I know it can be easy to miss! 🙂 I can’t wait to hear what you think of this mug cake, Marcia!
Hi Amy, do you know if the Greek yogurt could be substituted with dairy free yogurt- oat or coconut-based? I imagine the oat-based would fit better given the oat flour… just trying to make it vegan! Any input would be appreciated!
Yes, either non-dairy yogurt option should work! 🙂 I’d love to hear what you think of this mug cake if you end up making it, Nicole!
Hi,
Thank you so much for sharing your delicious recipes! Could I substitute almond flour? Keto doesn’t allow oat flour. I New to this, so I am unsure how alternative flours work. Thanks again,
Jenny
I really appreciate your kind words and interest in my recipes, Jenny! If almond flour is the only flour you’re able to consume, you can substitute it in this particular recipe. You may need to add a touch more because it’s less absorbent than oat flour, and your mug cake will turn out a bit denser (and possibly collapse while cooling). As long as you don’t mind that texture difference, the flavor should remain about the same! 🙂
I’d love to hear what you think of this mug cake if you end up making it!
Thank you for your response. I definitely will let you know. I will be trying this soon. The texture is a bit different with almond flour, for sure! I have found a brand that is more like the ” other” flours. It’s really really fine. Expensive of course, but hopefully it is close to the oat coconut, wheat, etc flour.
It’s my pleasure, Jenny! I’m happy to help. 🙂 I’m really looking forward to hearing what you think of this mug cake!
Hi Amy, Have you tried unsweetened powdered cacao instead of cocoa powder?
I really appreciate your interest in my recipe, Ellyn! If you click on the pink “unsweetened cocoa powder” link in the Ingredients list (my links are the pink colored font — I know it can be easy to miss that detail!), then you’ll see the exact cocoa powder that I use. The container’s label includes its cacao content. If that’s similar to the ingredient that you had in mind, then there’s a good chance that it’ll work. 🙂
I’d love to hear what you think of this mug cake if you try making it!
Great, I’ll give it a try. Thanks for your response
My pleasure, Ellyn!
Not sure what I did wrong, I read everything before starting. I used a kitchen scale. The only change I made was the sugar which I read you said was 2-3 tbsp of sugar. It was VERY thick. I baked it either way but it wasn’t good. Any clue where I messed up?
It means a lot that you tried my recipe, Adriana! That sounds disappointing and not like how this mug cake is supposed turn out, so I’m happy to help figure out what happened. In order to do so, I have some questions for you! 🙂
Was it the taste or texture that wasn’t good?
Did you make any other substitutions or modifications to the recipe, other than the granulated sugar?
How much granulated sugar did you use?
In Step 2, did you add the sugar to the first or second bowl?
When you used a kitchen scale to measure, did you just use it for the oat flour, cocoa powder, and Greek yogurt? Or did you use it for any other ingredients?
You mentioned it was thick — I’m assuming you meant the batter? Was it thick like muffin batter or really wet cookie dough, or was it as thick as bread dough?
Do you know the wattage of your microwave?
Did you use 30% power to cook your mug cake?
How long did you microwave it?
When you removed the mug cake from the microwave, can you describe the top’s appearance? Was the very center still a little underdone? Or was it fully cooked and totally set?
I know I just asked a LOT of questions, but I’ll have a much better idea of the culprit and how to fix it once I know your answers to all of them!
Was it the taste or texture that wasn’t good? The texture was rubbery, I didn’t bother tasting it cause I was mortified after seeing how it came out
Did you make any other substitutions or modifications to the recipe, other than the granulated sugar?
Only the sugar nothing else
How much granulated sugar did you use? 25 grams
In Step 2, did you add the sugar to the first or second bowl?
I “creamed” the sugar with the liquids
When you used a kitchen scale to measure, did you just use it for the oat flour, cocoa powder, and Greek yogurt? Or did you use it for any other ingredients? I used the scale for all the gram measured ingredients
You mentioned it was thick — I’m assuming you meant the batter? Was it thick like muffin batter or really wet cookie dough, or was it as thick as bread dough? It was thicker than brownie batter but not cookie dough thick
Do you know the wattage of your microwave? I baked it
How long did you bake it? 10 min
When you removed the mug cake from the microwave, can you describe the top’s appearance? Was the very center still a little underdone? Or was it fully cooked and totally set? It was fully cooked, it resembled thick eggs, I’m not sure how to properly describe that
Thanks for sharing your answers, Adriana! If I’m understanding correctly, it sounds like you used the modification to bake this mug cake in a traditional oven, rather than microwave it. Is that true?
If so, did you use a regular conventional oven or a countertop oven?
If a countertop oven, do you know the make and model, by any chance?
What oven temperature did you use?