Keto Mug Brownie
Published February 20, 2021 • Updated March 12, 2026
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Fudgy, chocolatey, and only 6 net carbs. This is my go-to when I need a chocolate fix without blowing my macros. Mix everything in a mug, microwave 60 seconds, and you have a warm, gooey brownie. Late-night craving? Done.
I have made hundreds of mug cakes over the years, and most of them were terrible. Dry, crumbly, tasting like almond flour with a faint suggestion of chocolate. This one took me several rounds of testing to get right, and the ratio is everything. 1/3 cup almond flour paired with 1 tablespoon heavy cream creates a batter that holds together without going gummy or falling apart like every other mug dessert I have tried.
What makes this a real brownie and not just a chocolate mug cake is the fudgy center. Pull it from the microwave when the center still looks slightly wet. It sets as it cools, and you end up with that dense, gooey texture a brownie should have. If you wait until it looks fully done, you have already gone too far. Reader Lindsey put it well after trying dozens of other recipes: the heavy cream is what makes the difference. My microwave is 1000 watts, and 60 seconds is the sweet spot. If yours runs hotter (most newer models do), start at 45 seconds and check. You want the center to jiggle slightly when you pull it out.
This is also completely egg-free. No egg means no spongy texture, no binding issues, and one less ingredient to think about. The butter and heavy cream do all the structural work, which is why this stays fudgy instead of turning into a mug cake. I keep the ingredients for this stocked at all times because my kids request it on weeknights, and I can have it mixed and cooking before they finish asking.
The single-serve format is the other thing I love about this. No leftover pan of brownies sitting on the counter at 10pm. One brownie, one mug. I make exactly what I want and there is nothing left over to negotiate with later. If you need two (my daughter started stealing mine, so I make two mugs every time now), just double the recipe into a second mug. Do not try to double it in one mug or it will not cook evenly.
A splash of vanilla extract in the heavy cream is something I picked up from a reader, and now I do it every time. It makes the chocolate taste more like chocolate, which sounds strange but works.
If you are looking for more low carb chocolate desserts, I have a fudge recipe that scratches a similar itch in a different format. My chocolate mousse is what I make when I want something lighter. For a full batch to keep in the fridge all week, my low calorie brownies scale up well. The smores bars are a completely different kind of chocolate fix. And for something you can crumble on top, my no bake cookies work surprisingly well as a brownie topping.
Explore 683+ keto recipe videos with step-by-step instructions, tips, and tricks to make keto easy.
Ingredients
1 tablespoon butter, softened -
1 scoop Cacao Bliss or 1.5 tablespoons cocoa powder
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1 tablespoon monkfruit sweetener
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1 tablespoon heavy cream
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1/3 cup almond flour
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pinch of salt
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1 tablespoon sugar-free chocolate chips
Step by Step Instructions
Step by Step Instructions
Add ingredients
Add all of your brownie ingredients to a small bowl, except the chocolate chips. Microwave for 20 seconds. This will help soften the butter further so you can easily mix it.
Nutrition disclaimer
The nutrition information provided is an estimate and is for informational purposes only. I am a Doctor of Pharmacy (Pharm.D.); however, this content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician or other qualified health provider before making any lifestyle changes or beginning a new nutrition program.
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Get My Macros + Recipes →Frequently Asked Questions
Can I bake this in the oven or air fryer instead of the microwave?
I have tested all three methods with this recipe. Oven: 350F for 12-14 minutes in a ramekin. Air fryer: 300F for 8-10 minutes. The microwave version stays the gooiest in the center, but the oven gives you the best edges. I go back and forth depending on how patient I am feeling.
Why did my brownie come out dry or rubbery?
Nine times out of ten, it is the microwave wattage. My microwave is 1000 watts and 60 seconds works perfectly. If yours is higher (most newer ones are 1100-1200W), start at 45 seconds and check. The center should still look slightly wet when you pull it out. It keeps cooking from residual heat and sets as it sits. If you microwave until it looks done, it is already overdone.
Is this keto mug brownie egg-free?
Yes, and I left the egg out on purpose. I tested versions with and without an egg early on, and the egg-free version stays fudgier. Eggs make mug cakes spongy, which is the opposite of what I want from a brownie. The butter and heavy cream handle all the binding.
Can I make a peanut butter swirl version?
Drop a teaspoon of peanut butter on top of the batter before microwaving and drag a toothpick through it once or twice. I do not mix it in because I like the ribbons of peanut butter running through the chocolate. It adds about 1g net carb depending on your brand.
Can I use a different sweetener instead of monkfruit sweetener?
I use monkfruit sweetener because it measures like sugar and I like the taste. Erythritol works cup for cup as a swap. Allulose works too but it does not firm up the same way, so the brownie will be softer (not necessarily a bad thing). I would avoid liquid stevia here because the batter is already wet enough and the extra liquid throws off the texture.
What if I don't have almond flour?
Sunflower seed flour swaps in at the same measurement, which is my go-to for nut-free. Coconut flour works too but I only use about 2 tablespoons because it absorbs so much more liquid. I learned the hard way that a full 1/3 cup of coconut flour turns this into a dry mess.
How do I make the chocolate drizzle topping?
I melt a few tablespoons of sugar-free chocolate chips in the microwave at 30-second intervals, stirring between each one, until smooth. Adding half a teaspoon of coconut oil thins it out so it drizzles better. Pour it over the brownie while it is still warm and it sets into a thin shell as it cools.
How can I store leftovers?
I usually eat the whole thing right away, but if you need to save it, let it cool completely, cover the mug, and refrigerate for up to 2 days. Reheat in the microwave for 10-15 seconds. It will not be as gooey as fresh, but it holds up better than most mug cakes I have made.
Made this on a whim when my daughter got home from school last week and found me eating straight from the mug (turns out 60 seconds really is done, I was skeptical). She wanted one immediately so I handed mine over and she ate the whole thing before I could reclaim it. What got me was she said it tasted like the brownie mix we used to make before I went keto, not keto anything, and she would know because she still eats that stuff. Been making two mugs every time since.
Two weeks into keto and this was my first attempt at a dessert. I had no idea what I was doing but 60 seconds later the center was genuinely gooey, not what I expected from a mug at all.
I've tried so many keto mug brownie recipes and most come out with this weird spongy texture, or they're dry, or you can taste the almond flour way too much. This one is actually fudgy. Like, genuinely fudgy. The heavy cream is what's doing it, I'm pretty sure, because I've made them without it and you can tell. The chocolate chips half-melting into the top while it's still warm is a nice touch too. I used Cacao Bliss because I had it on hand and the chocolate flavor was so much deeper than when I've just used straight cocoa. I usually add a few extra chips because I can't help myself. Six net carbs and it doesn't taste like settling for something.
The heavy cream is the whole thing. I noticed the same with Cacao Bliss - the added fat does something cocoa powder can't match on its own. Extra chips are not a mistake.
My teenager watched the microwave count down with complete skepticism. When he tasted it he stopped mid-bite and stared at the mug. The almond flour gives it a different density than a regular brownie (4-star, not 5), but a fudgy chocolate center in under a minute is hard to argue with on a cold night.
The stare gets me every time. He's not wrong, almond flour runs heavier than wheat and that won't change. Fudgy center in under a minute is a separate thing.
Pulled mine at 50 seconds instead of the full minute and that was the move. Center stays gooey the way a brownie should. I also added a tiny splash of vanilla to the heavy cream and it deepens the chocolate somehow. Worth trying.
50 seconds works. And vanilla in heavy cream is one of those things that sounds weird but makes the chocolate taste more like chocolate. Hadn't tried it in this one yet.
Mug brownies have let me down so many times I almost skipped this one. The almond flour base actually holds up, and it's as good as any full-batch keto brownie I've made. Something about the ratio just works.
The ratio in this one took me a few tests to land on. That 1/3 cup almond flour with just a tablespoon of heavy cream is what keeps it from going gummy or falling apart like most mug cakes do.
My kids are so picky about dessert (like, annoyingly picky) so I wasn't expecting much when I made this for them on a cold Tuesday night. Both of them asked for seconds. The 60-second microwave thing felt too good to be true but that gooey center was real. We're making these every week now.
Picky kids asking for seconds is the best win with this one. My kids are the same way with sweets so I always keep the stuff for this stocked.
Evidently my microwave cooks fast. 1 minute was too much. Turned out a bit dry and real dense towards the center and not in a good way.
I should have read comments first.
But the taste was there, chocolatey sweet bomb. just dry. I'll try again another day.
Yeah microwave wattage is all over the place. Mine's 1000W, if yours is higher start at 45 seconds and check. Should still look slightly wet in the center when you pull it.
Your recipes are always written so well--very easy to understand and taste delicious! Thanks.
Sharon
My 10pm chocolate fix. Try a pinch of flaky salt right after it comes out, Sharon.
Annie, I see a glaze of drizzled chocolate in the images. How does one make that??
I melt a few tablespoons of chocolate chips in the microwave at 30 seconds intervals, stirring in between, until melted. You can also add 1/2 teaspoon of coconut oil in there to thin out the melted chocolate. Then drizzle on brownies.
It didn’t come out for me :( it crumbled and was dry and burnt in the centre. I guess I overmicrowaved. But is that why it crumbled too? Also didn’t taste like a brownie, more like a dry chocolate cake. No ooey, gooey chocolate brownie. Maybe I’ll try it again but I don’t know where I went wrong. Does it have to rest longer? Would an egg help with binding?
It sounds like you overbaked it. It shouldn't come out dry and burnt. It's gooey and then as it cools, it hardens up. All microwaves are different so if you decide to make them again, lower the microwave power and maybe the baking time and adjust from there.
Mine turned out the same as yours, crumbly and dry but very tasty. Just made it again with an added 1 teaspoon water...PERFECTION! 1 minute, not 1 minute and 15 sec.
Ahh so sad... your recipe “Print Recipe”button doesn’t work! Lovely brownie video! Will write them all out and make them one day soon!
I'll look into the print button. Thanks for letting me know! :)
Where can I find a small square glass dish like you use for the brownie?
It was part of a glass storage container pack that I got from Amazon.
Annie, this was amazing and turned out perfect. My kids gobbled them up not knowing they were keto. I will be making these brownies again and adding nuts.
Nuts are a great call. Press them into the top of the batter right before it goes in so they don't sink. Walnuts or pecans both work.