Kirbie's Cravings

Keto Brownie Mug Cake

This single serving brownie is super fudgy and cooks in the microwave. It is also low carb, gluten free and keto-friendly. It is a delicious and easy recipe.
close-up photo of a brownie mug cake

Last month I shared my keto brownies recipe. Since then, I’ve been working on a single serving microwave version so that I can satisfy my brownie cravings without having to bake a whole batch of brownies. This brownie is super fudgy, chocolatey and satisfying.
overhead photo of a keto brownie mug cake

Texture of the Brownie

The brownie has a very fudgy texture. However because there is no egg acting as a binding agent, the crumb is a little loose. You will not be able to remove this brownie in one piece from the mug, so it is best eaten in the mug. I also don’t recommend adding an egg to the recipe as it will change the texture of the brownie and make it less fudgy and more like a cake.

Type of Mug to Use

This can be made in an 8 oz microwave safe mug because it will not rise very high. Like any normal brownie, it is very rich and dense. The brownie will only rise about halfway up the mug when finished. (For photos purposes, the recipe was doubled so that you can clearly see the brownie).

Because this brownie does not rise very high, you can also make this in a microwave-safe ramekin instead of a mug.
photo of a keto brownie mug cake

If you like this brownie mug cake you might like my Keto Nutella Brownie Mug Cake and Keto Blueberry Mug Cake, too.

Keto Brownie Mug Cake

Servings: 1
Prep Time: 10 minutes
Cook Time: 1 minute
Total Time: 11 minutes
Course: Dessert
Cuisine: American
A single serving brownie that is super fudgy and cooked in the microwave. This brownie is also low carb, gluten free and keto friendly!
4.86 from 28 votes


  • 2 tbsp unsweetened cocoa powder
  • 2 tsp coconut flour
  • 1/2 tsp baking powder
  • 1 1/2 tbsp Swerve granular sweetener
  • 1 1/2 tbsp heavy cream
  • 1 1/2 tbsp water
  • 1 tsp extra virgin olive oil
  • 1 tbsp chopped dark chocolate


  • In a microwave-safe mug (that holds at least 8 oz of liquid) add cocoa powder, coconut flour, baking powder and Swerve. Mix with a small whisk to break up any clumps and mix until evenly combined.
  • Add in heavy cream, water and oil. Whisk until batter is smooth. Sprinkle surface with dark chocolate.
  • Cook brownie in the microwave at full power for about 60-80 seconds. I like the brownie to be extra fudgy and slightly underdone, so I cooked mine to 65 seconds. Allow brownie to cool a few minutes before eating. Brownie is best eaten warm.


  • For the sugar substitute, I used Serve Granular Sweetener.* If you have a favorite keto friendly sugar substitute, it will likely work with this recipe.
  • I used a 1000 watt microwave. You may need to adjust time and/or power if you are using a different wattage.
  • Make sure to only add 2 teaspoons (not tablespoons!) of coconut flour. Coconut flour is highly absorbent which is why you only need a little. Also make sure not to leave out any of the liquid ingredients, otherwise your batter will be too dry.
  • For the dark chocolate, you can use  Lily's dark chocolate bar* which is sugar free or a dark chocolate with at least 80% cocoa. One of my favorite keto friendly chocolates to use right now is Endangered Species 88% Cocoa.*
  • Because there is no egg acting as a binding agent in this recipe, the crumb of the brownie is a little loose. You will not be able to remove this brownie in one piece from the mug so it is best eaten in the mug. I also don't recommend adding an egg to the recipe as it will change the texture of the brownie and make it less fudgy and more like a cake.
  • The heavy cream gives this brownie an extra richness and fudginess. If you do not have any heavy cream, you can substitute with milk and add an additional 1/2 tsp olive oil (so a total of 1 1/2 tsp olive oil in the recipe). The brownie will still work but it won't taste quite the same.
  • The brownie will only rise about halfway up an 8 oz mug when finished. For photos purposes, the recipe was doubled so that you can clearly see the brownie.
  • *Some of the product links contained in this post are affiliate links. Much like referral codes, this means I earn a small commission if you purchase a product I referred (at no extra charge to you).
Estimated Nutrition Information is calculated with Lily's dark chocolate. Nutrition does not include carbs from erythritol


Serving: 1brownie, Calories: 203kcal, Carbohydrates: 13g, Protein: 4g, Fat: 19g, Saturated Fat: 9g, Cholesterol: 30mg, Sodium: 259mg, Potassium: 165mg, Fiber: 7g, Sugar: 1g, NET CARBS: 6g

The nutrition information provided are only estimates based on an online nutritional calculator. I am not a certified nutritionist. Please consult a professional nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.

Did you make this recipe?I'd love to see it! Mention @KirbieCravings and tag #kirbiecravings!


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90 comments on “Keto Brownie Mug Cake”

  1. How can I convert this recipe to use almond flour instead? 

  2. I don’t know what went wrong, but my large mug overflowed goo all over by 30 seconds!!!  Couldn’t get a fudgy/cake texture even by 90 seconds, and lost half the batter on the mic tray!

    • I’m sorry to hear that. The cake should not overflow since it does not rise much. Did you make any changes to the recipe?

  3. Ultra fudgy deliciousness! This saved me! It’s soooo satisfying. Mega craving killer! Thank you so very much! ??

  4. This ya by far the best keto brownie I’ve had. Love it with a little SF whipped cream. Thank you!

  5. Just made this. One of the best keto mug cakes around. I made the first one by the recipe. It was delicious. I like more cakey texture, so I added two quail eggs and it came out perfect. Great recipe. 

  6. How many actual carbs is this? Not net carbs

    • both are given in the nutrition information

      • The nutrition information in the recipe says that there are 13 grams of carbohydrates and 6 grams net carbs for this recipe. This cannot be quite right, though, as Swerve granular sweetener has 4 grams per teaspoon–there are four and one-half teaspoons in 1 1/2 tablespoons–so there are at least 18 grams of carbohydrates in just the Swerve. Are the measurements wrong, or is the initial carb count incorrect?

      • As explained in the notes, I do not include carb from erythritol in the carb count. The reason I do this is because people get confused when they see the high carb count if it includes the carbs from erythritol. There is no separate category in the nutrition label for carbs from erythritol so I exclude them.

      • Yes, you are doing “net carbs”–this person asked for “actual carbs”–and that was not included. So, the actual carbs were not included in the nutritional information, as I was trying to point out (perhaps badly)–this recipe probably will not work for a person with diabetes, which may be why the original question was about “actual carbs.”

        Swerve also contains oligosaccharide, by the way, not just erythritol. I was asking about measurements as a tablespoon and a half is a lot for one cake. Most muffins I make only use about a teaspoon for a muffin. I think I will skip this recipe, as it seems dicey for someone with health issues rather than just someone concerned with weight loss.

      • I’m sorry for any confusion. The recipe provides a carb count but without the erythritol, which I explained is because there is no category for carbs from erythritol in my nutrition label. The recipe is labeled “keto brownie mug cake” so the majority of people reading it are looking for net carbs. I am aware Swerve isn’t just erythritol but all the carbs in Swerve are from erythritol as stated in their nutrition label.

  7. WOW! This the best! Was looking for a recipe without almond flour – this was perfect and wonderfully rich!! A keeper!

  8. Very good thank you so much !!!!!!!! it was plain fudgey goodness also topped with pecans and sf camel syrup

  9. I made this recipe and didn’t have the heavy whipping cream (I used almond milk and extra olive oil) and all I had was 100% unsweetened cocoa chocolate bars. It satisfied my cravings for chocolate but, left a bitter aftertaste that while I could live with it, the family couldn’t and didn’t like it.

    The recipe took me less than five minutes in total to make and was a saving grace that kept me from cheating on my diet and feeling bad about myself. I will definitely play around with the recipe and might substitute a bit of unsalted butter for some of the oil to tweak it to my liking.

  10. I tried this recipe with and without 1 egg. I think you just forgot to add an egg to your recipe ?

  11. Very good, very rich! I used avocado oil, instead of evoo, and also threw some chopped pecans in there. Wish I had some low carb vanilla ice cream right now. I’d be in hog heaven.

  12. Thank you for sharing this absolutely delicious recipe.  I have seen many mug cake recipes and always wanted to try one.  I am so glad I choose this one to start with.  I do think next time I need to cook it just a tad longer, but that’s on me.  I think I will add some pecans or some Lily’s White Chocolate to the top just to mix things up a little.  Possibilities are endless.  There will definitely be a next time.  

  13. This was very yummy! However I’ve one question about the nutrition. Trying to work out my net carbs per portion.
    Are the measurements actually based on only 1g?
    Thank you for feeding my sugar craving!

  14. Delicious! It’s crazy how simple this was but how tasty it turned out. I substituted both the heavy cream and olive oil with an avocado oil spread and oat milk and added about 1/2 tbsp of vanilla. I also used some pieces of a dark chocolate mint bar pieces instead of just dark chocolate. Oh and lastly I happened to have some sweetened whipped coconut cream to put on top which made it nonketo but damn delicious. This is such a winner, especially for those who want to stay away from grains and sugar in general. Thanks so much! (Wish I made two at the moment :P)

  15. Phenominal!!!

  16. Taste like a real brownie!!!! So good!!!! 

  17. Had again this morning with breakfast. So yummy!
    Love you Kirby!

  18. I have been craving brownies so much lately and this really hit the spot. I actually didn’t have a chocolate bar, so I just left it out. I also stirred in 3 pecan halves roughly chopped. It turned out like heaven in a mug. It was so good that I can’t imagine how the candy bar addition could make it better – but I’ll try it again when I get a candy bar. You helped this girl stay keto tonight, and I thank you!

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