This keto brownie in a mug is gooey and decadent, and serves just one person. It’s the perfect single-serve dessert when you need chocolatey goodness but you don’t want the leftovers.
Add a scoop of keto ice cream for the ultimate indulgence.
Don’t say I never do anything nice for you. Because not only do I give you the recipe for this delicious keto mug brownie, but I also provide you with three different ways to bake it!
I show you how to bake this same recipe in an oven, in an air fryer, and in a microwave. So no matter what equipment you’ve got on hand, you can enjoy a delicious keto dessert.
How’s that for a full service keto food blog?
Single Serve Keto Brownie
Usually when I make keto brownies, it’s the “whole pan to feed a crowd” type of recipe. My family can put a pretty good dent in a pan of brownies before you can bat an eye.
But sometimes I need a treat that is just mine, and mine alone.
I developed this keto mug brownie almost 6 years ago now, but I decided it needed an update. My goal was to reduce the carbs but make it just as gooey and rich as it always was.
I also experimented with the cooking method, to see if I could get the same results in an air fryer and a microwave.
And it worked perfectly every way I tried it. Now we all have more options and you can’t beat that!
Ingredients
This keto brownie takes basic low carb ingredients that you can find in almost any grocery store. You will need:
- Butter
- Keto sweetener: I recommend using a powdered sweetener like Swerve Confectioners so it blends in better.
- Egg: You just need two teaspoons and carton eggs or egg whites work well.
- Vanilla extract
- Almond flour: Use finely ground, blanched almond flour for best results.
- Cocoa powder
- Baking powder
- Water or cold coffee
- Chopped nuts or sugar-free chocolate chips (optional)
How to make keto brownie in a mug
This recipe is ridiculously easy to make, and you have three different ways to bake it. Here are my best tips for getting it right:
The brownie batter
- Melt the butter: Use a microwave safe bowl and cook on high until just melted but not too hot.
- Whisk in the sweetener: I recommend a powdered sweetener so that it dissolves well.
- Add the egg and vanilla: You need such a small amount of egg but it’s important to measure it out carefully. You can whisk a whole egg, or use eggs from a carton.
- Stir in the dry ingredients: Make sure everything is well combined and break up any clumps in the almond flour and cocoa powder.
- Add a little liquid: At this point, the batter will be quite thick. Add 1 tablespoon of water or cold coffee to thin it out.
- Sprinkle with some toppings: I really like some finely chopped pecans, for crunch. But a few keto-friendly chocolate chips work too.
Oven method
You can use a regular oven or a smaller countertop oven. Bake it at 325ºF for 10 to 15 minutes – the less you bake it, the more gooey it will be.
Air fryer method
This may be my favorite method, as I think it produced the best results. It was like a cross between a brownie and a chocolate lava cake!
Bake it at 325ºF for 7 to 9 minutes. Again, the less you bake it, the gooier it will be.
Microwave method
In a hurry to enjoy this keto mug brownie? You can cook it in less than 1 minute in your microwave! It does end up a little more spongy, as microwave cakes usually do. But it’s still delicious.
I found that starting and stopping the microwave in 15 second increments helped keep the brownie from spilling over the ramekin. Check on it frequently so you know when it’s the right consistency for you.
Frequently Asked Questions
Coconut flour won’t work in this recipe but you can use sunflower seed flour. It is a 1:1 replacement with almond flour.
Absolutely! Use coconut oil or another dairy-free alternative to butter. If it’s a liquid oil like avocado, there is no need to melt it first.
Yes but do keep in mind that sweeteners such as allulose can affect the consistency. I find that baked goods end up more puffy and cake-like when I use allulose as the main sweetener.
Absolutely! Just double or triple the recipe and divide the batter among more ramekins. Cook as desired.
Keto Mug Brownie Recipe
Ingredients
- 1 tbsp butter
- 1 1/4 tbsp (1.5 tbsp) powdered Swerve Sweetener
- 2 tsp whisked egg, (can use carton eggs or egg whites)
- 1/8 tsp (0.13 tsp) vanilla extract
- 1 tbsp almond flour
- 1 tbsp cocoa powder
- 1/8 tsp (0.13 tsp) baking powder
- 1 tbsp water or cold coffee
- 2 tsp (1 tsp) chopped pecans, (optional)
Instructions
- In a small microwave safe bowl, melt the butter in the microwave. Stir in the powdered sweetener until well combined, then stir in the egg and vanilla extract.
- Add the almond flour, cocoa powder and baking powder, then add water and stir until the mixture is smooth.
- Transfer the batter to a small (4-ounce) ramekin and sprinkle with chopped nuts, if desired.
To bake in the oven (or toaster oven)
- Preheat the oven to 325ºF and bake the brownie 10 to 15 minutes, depending on how gooey you want it to be.
To bake in an air fryer
- Preheat the air fryer to 325ºF and bake the brownie 7 to 9 minutes, depending on how gooey you want it to be.
To bake in a microwave
- Microwave on high in 15 to 30 second increments, stopping the microwave in between so that it doesn't spill over. A total of 45 to 60 seconds should be enough.
Video
Nutrition
Free Bonus: Secrets to Keto Baking!
Sign up for your favorite recipes delivered straight to your inbox plus get our FREE bonus: Secrets to Keto Baking!
I made these tonight for my husband and I. I used granular erythritol and mixed it well with the butter like one commenter mentioned and it was great. No grittiness. The brownies were to die for! I added some pecans as well. So good. I was so happy they were made with things I had in the kitchen. (I never have protein powder $$) We will be making again and again…maybe with a cheesecake layer on top next time? yum.
Oh, and I added a pinch of salt…because I add salt to just about everything 😉
This is an absolutely amazing brownie!! I use 2 T sweetener and microwave for one minute. Chocolate heaven!!!! Thanks for sharing!!!
Thanks for sharing your tips!
What do you think about substituting 1 Tbsp. almond milk for the 1 Tbsp. water?
Totally fine.
Are there other sweetener options (and measurements)?
It all depends on what you want to use.
Sorry. Nothing artificial. Would rather use straight up sugar, maybe coconut sugar or maple syrup.
Hi there. Apparently you are unaware that Swerve IS natural? I don’t use artificial sweeteners…ever.
I was worried about this too. Swerve is natural WHAT? I had not heard of it until this recipe.
Erythritol: a naturally occurring sugar alcohol found in fruits and fermented foods. Oligosaccharides, a natural prebiotic fiber similar to inulin. Check out their website, it will give you more details.
Here it says says erythritol is made from corn. https://www.decodedscience.org/erythritol-made-manufacture-low-calorie-sugar-substitute/42248
Is Swerve made from corn?
It’s made from a glucose syrup that can be made from either sugarcane or corn. But it’s fermented, so there is neither any sugar cane or any corn left after the microbes that are introduced to the glucose syrup have digested it and fermented it. There is no glucose either.
I do realize that it has neither “corn” nor glucose in it, but for me it is also about what industries I want to support. Unless it is heritage corn erythritol is made from, then it is not an industry that I choose to spend my money on. Everybody has options. We all decide which options we choose. ?
Can you microwave this recipe? Looks awesome ❤thanks ??
Thank you Sandra, was wondering how to measure just 2 tsps. Great idea!
I also only have granulated swerve … Would that change the texture and taste? I need to get powdered
It might end up a bit grittier.
Try pulsing it in the blender with a bit of cornstarch for a few seconds.
I used regular swerve and it worked fine, i just wisked it into the melted butter for a minute or two to “cream” it together. No grittiness!
Good to know!
If I don’t have a ramkin can you use a glass Pyrex?
I think that should work.
I just finished eating a Single Serve Chocolate Chip Brownie with a hot cup of coffee with lots of cream. What a splendid way to pamper yourself in the mid-afternoon.
Delicious recipe, perfect portion and super easy. Since I separated a fresh egg to get the egg white, I at first had a little problem measuring out the 2 tsp of egg white. (Part of the white in the tsp wanted to go back into the bowl.) I beat the white a little with a small whisk and was able to measure out 2 tsp perfectly. Challenge met and resolved. Now I’ll use the rest of the white and yolk for breakfast tomorrow. Thank you for all that you do to make life good in the low carb, gluten free world
Thank you for sharing this! I’m usually the only one in the house eating chocolate cake or brownies, so when I need a quick chocolate fix, I often make a mug cake in the microwave (so I don’t end up eating a whole pan of brownies all by myself). This is a life saver!
this looks great. Do you think it would work in the microwave? If not, I’ll definitely be trying it in the oven, but thought I’d ask. Thanks for the awesome recipes! Just made your coconut cheesecake for Easter!
I think several people have done it in the microwave for a minute or 90 seconds.
I just made this and OMG. Exactly what I needed this afternoon. I skipped the chocolate chips and grated some dark chocolate on top instead. so dang good!!
So glad you liked it, Karly. Hows the keto diet going?
Carolyn, thanks for the recipe! I can’t wait to try it. Was wondering for other family members sake, is there a substitute to nut flour I can use that works! If now, they will just have to watch! Thank you.
Sure! Try sunflower seed flour.
Is there a ‘feeds 12’ version of this recipe? 🙂
Yup and it’s called….times everything by 12 😉 I have actually made a quadruple batch, that worked out well.
Would this work with vegan butter and flax seed meal (vegan eggs)?
This one might, actually. It’s worth a try! At worst, you’d end up with a gooey chocolate concoction that would still taste great.
I just made it in microwave and it was delicious
How many minutes in the microwave? I’m dying to try this!
About 30-40 seconds in the microwave works a treat.
I also made this in the microwave recently. Really good whether gooey or cakey.
This was fantastic. Husband ordered out some Chinese food and I was jealous, so I whipped this up and wow, it was beyond my expectations. So gooey and rich, it really was like a regular brownie, didn’t feel like a low carb treat at all.
Yay!
What type of egg white did you use…..powdered or real? Thanks, looks yummy
Carolyn, I was practically drooling at your description of different types of brownies, but the photo put me over the top (so to speak). Guess what I’m having for dessert tonight? 😉
Thank you!
Mmmmm…yes please! Looks awesome Carolyn,
Yum! Definitely going to try this!