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
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Great in the microwave!
Just made your mug brownie for the first time. A perfect little sweet treat. Nice and fluffy. I even forgot the baking powder and it was still fluffy. I used brewed coffee and some pecans. I microwaved it and it was very tender. I didn’t top it off with anything but it would be delicious with keto ice cream or whipped cream. Only took minutes. A definite must try! Thank you for the recipe.
Love this recipe! We had all of the ingredients and it tastes so much better than the other keto mug cake recipes we’ve tried – it actually tastes like a brownie!! 🤗 Thank you!!
Made this in the air fryer and it was just what I needed. Thank you.
Great comfort food! I made it in the microwave using 15 sec increments for a toatl of 45 sec! Yum, it hit the spot!
OH YEAH this is exactly what I was looking for! Just wanted something simple yet decadent to make for a little snack on a cold, rainy night. This is PERFECT!!! Only took a minute to throw together and came out so perfect. I put a few chocolate chips on top at the end so they melted and then topped with some fresh whipped cream. YUMMMM!!!! Good thing it’s a small size so I’m not tempted to eat too much. The flavors are so rich and the coffee takes the chocolate flavor to the next level.
The best single serve desert I’ve found yet! I served it with keto vanilla ice cream and it was soo good! Even my non-low carb husband and daughter loved it!
(I did add a pinch of sea salt to mine Bc I’m not a huge chocolate person).
Great to hear!
Hi! New to keto……the sweetener you use in this has 8g of carbs alone so not sure where the 5.6 comes from? I count total carbs….is your count for net carbs? Thanks!
Hi Mac… erythritol does not spike blood sugar and should not be counted as a carb. I discuss this in the nutritional disclaimer at the bottom of each blog post.
This hit the spot perfectly for a comforting chocolate dessert. Delicious ending to the day!
YUM. I used a full egg, and just added more almond flour & cocoa to make it less liquidy.
Just made this for me and my husband, he was craving chocolate. He love it!!!
Excellent!
So good!
I made this brownie and enjoyed it so much. I live alone so I look for food items with small servings. Thank you
I am so glad!
I just use a whole egg in my mug cakes…nothing bad has happened yet! lol ups the protein by a couple grams but doesn’t change the carbs! I also do one with just coconut flour and ground flax or psyllium husk. Ups the fiber! I find mug cakes the most forgiving of the fast easy treats! I eyeball everything! That’s with over 7 yrs of low carb living experience I guess I am so familiar with my staple ingredients you kind of develop a feel for how to eyeball a few recipes! I use your site daily! Thanks again for all you do!!!!
Hello,
I completely botched making an adjusted version of this today 😀
I eyeballed the butter (1+1/2 tbsp, too much) and didn’t want to use only a part of an egg so I tried some flaxseed flour (1/2 tsp, not enough) and water (an extra 1 tbsp, way too much). The result was a dark porous substance swimming in buttery water. It was still edible, chocolatey and sweet, but certainly not a brownie. 😀 Serves me right for messing with the recipe and not even looking up the ratio for a flax egg. Maybe it would have turned out alright with at least a full tsp of flaxseed flour.
This received rave reviews from dear husband. Topped with chopped nuts & Lily’s dark chips & used a smidge of espresso powder in the batter. Next time I’ll experiment with keto caramel. Mmmm. Thanks for sharing!
Great to hear!
Oh, my!! This really hit the spot. I’ll be adding this to my regular rotation. I love everything dark chocolate, so I used 2t regular cocoa powder and 1t black cocoa powder. Yummy!!
I accidentally used coconut flour, I didn’t realize it until putting away ingredients.
It wasn’t exactly what I thought it would be but not too bad at all, actually it was pretty good😋
I don’t suppose you could use just egg yolks? I have two that I don’t know what to do with.
You might be able to, actually. It would make it even gooier!
0h yum! Made this for supper [don’t normally eat supper] and it was amazing with some sf chocolate chips and some All Day carmel! I don’t normally like almond flour products but this is a keeper!