Kirbie's Cravings

3 Ingredient Flourless Peanut Butter Mug Cake

photo of a flourless peanut butter mug cake

This easy flourless gluten free peanut butter mug cake is only three ingredients. It cooks in the microwave and is ready in about 5 minutes.

Just like how easy this mug cake is, I’m going to keep this post simple and sweet.
close-up photo of the top of the cake
I’m quite tired. In the past 2 weeks, I’ve traveled out of town three times. And while I’m grateful for all the experiences, I’m also exhausted. I’m looking forward to being in my own home for an extended period of time and going back to my normal routine and back to my regular blogging schedule.
close-up photo of a spoonful of cake
But even in my exhausted state, I can make this five minute mug cake. And you can too.

I actually already have a flourless peanut butter mug cake recipe I really love. But I was playing around in the kitchen the other day and discovered I could create one with just three ingredients.

This cake is peanut buttery, but also light and fluffy. You won’t believe it’s flourless. If you have peanut butter, eggs, and sugar, I urge you to try it now.

Recipe updated with a new video! You can find all my recipe videos on my youtube channel as well.

If you enjoy this recipe, be sure to check out my cookbook* of nearly 100  mug cakes!

photo of the cover of 5-Minute Mug Cakes cookbook

*Some of the 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).

3 Ingredient Flourless Peanut Butter Mug Cake

Servings: 1
Prep Time: 4 minutes
Cook Time: 1 minute
Total Time: 5 minutes
Course: Dessert
Cuisine: American
This easy flourless gluten-free peanut butter mug cake is only three ingredients. It cooks in the microwave and is ready in about 5 minutes.
4.67 from 9 votes


  • tbsp creamy peanut butter
  • 1 tbsp + 1 tsp white granulated sugar
  • 1 large egg


  • Whisk all ingredients into an oversized, microwave-safe mug until batter is smooth and egg is fully whisked in. Microwave for about 1 minute. Let cake cool a few minutes before eating.



Serving: 1mug cake, Calories: 418kcal, Carbohydrates: 26g, Protein: 18g, Fat: 28g, Saturated Fat: 6g, Sodium: 291mg, Potassium: 380mg, Fiber: 2g, Sugar: 21g, NET CARBS: 24g

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!



Twitter Facebook | Instagram Pinterest


RSS | Email | Bloglovin

Related Recipes

Flourless Peanut Butter Mug Cake
photo of a peanut butter mug cake

Eggless Peanut Butter Mug Cake
photo of an eggless peanut butter mug cake

Nutella Swirled Pumpkin Mug Cake

3 Ingredient Flourless Peanut Butter Mug Cake

Subscribe to receive new post updates via email

don’t miss a thing!

Get new post updates via email:

267 comments on “3 Ingredient Flourless Peanut Butter Mug Cake”

  1. OMG! this is amazing! I made mine with Agave and it worked great! Had to use a soup bowl b/c we don’t have mugs, so I had to cook it a little longer. but none the less, thank you! this will help with my sweet cravings!

  2. This is BY FAR the best mug anything (cake, cookie, brownie, etc.) I’ve ever had!

  3. I was skeptical at first not sure about the batter but it turned out great and tasted good????

  4. I tried this after reading the many rave reviews on how “amazing” and “awesome” and “soooo good” it was and I honestly wasn’t all that impressed. It wasnt terrible but it certainly didn’t live up to all the hype and rave everyone else was giving…. I did it exactly to the recipe and directions and the only thing that made it good enough to eat was a lot of ice cream scooped on top. Would probably not fix again.

    • everyone has different tastes. sorry you didn’t love it! I don’t think it’s the most amazing thing ever, but for something that only takes three ingredients and less than five minutes, I think it’s pretty good!

  5. This cake is very good.   It is perfect for someone who has to have good protein in their diet.  Now I have found one more desert I can have.   Thank you.  
    I have hypoglycemia.   This is good for me. 

  6. You’re right!  I can’t believe there is no flour in there. Tasty treat that has ingredients that are always in my house.  I bet adding chocolate chips would be amazing! Thanks so much for this simple, delicious  idea!

  7. I was very skeptical, I can’t believe how amazing this is! Just saved me from going out and eating half my weight in ice cream, haha.

  8. OMG *____* 
    Just tried this as a break from studies and it doesn’t really have a cakey texture but oh god oh god oh god the taste is so mindblowingly fantastic…out of all the mug cakes I’ve tried, this is the probably the second or third that I’d love to try again!
    I could scrape out like a 2.5 tbsp of peanut butter only and after reading the comments, I used an egg beater to beat the batter. I made a ‘glaze’ with a bit of milk, margarine and Ovaltine and this is love <3
    Back to Organic Chemistry now :'(

  9. I just found this recipe and am going to try it this weekend!  From comments, this sounds like it comes out a bit like a souffle.  Mmmm.  

    Thank you for your recipes! 

  10. C’est vraiment bon et très simple à faire ????????????

  11. This recipe is a total game changer for me! I love low carb diets but the real struggle for me comes at night when I want something sweet, like cake, for dessert.  Often I give in to temptation and ruin a hard day’s work with sugar.  I substituted 3 stevia packets instead of the sugar and HOLY COW!!!! Totally satisfied my craving while staying with my diet! Thank you thank you thank you for this!!!!!

  12. This looks delicious! Just out of curiosity, how many calories are there? 

  13. Delicious! I’ve had many mug cakes, but not like this! I added some banana after I cooked it, super good!

  14. Hi. I made this cake and when I microwaved it, it had only risen about 1/3 of the way up the mug. The color was also a little darker than it was supposed to be. It was still good, but very dense. Do you know what I did wrong and how I can fix it? Maybe I overmixed the batter?

    • I don’t think it is from overmixing the batter. What kind of peanut butter are you using? If you’re using a natural peanut butter that needs to be premixed, that could be an issue if it wasn’t completely mixed. Also the sugar can be the issue. If you used more sugar than what the recipe called for, the cake will be denser and won’t rise as high. Or if your peanut butter is already pre-sweetened that could also cause too much sugar in the batter.

  15. I am on a gluten free diet and have had an issue with finding simple delicious deserts. I tried your recipe and I love it!! So moist and very good flavor, I added a little almond extract to it and it turned out amazing! Thank you so much!

  16. I tried to make it but it didn’t work, it looks disgusting, I think I did something wrong…

  17. So I tried making it and failed, it tasts like a very sweet omlet with peanut butter. I did something wrong.????

    • Sorry to hear your first try wasn’t successful. Make sure you completely whisk the batter. It’s best to use a mini whisk, and really mix with some force, like you would any other cake batter. It should be completely smooth, uniform, like any other cake batter and no egg streaks. It sounds like your egg wasn’t completely mixed. If it is completely mixed in, then it won’t have an egg taste.

  18. Hi Kirbie! I made this today and it was awesome! I added chocolate syrup and stirred the batter just a tiny bit for a marbled effect. I microwaved it longer than one minute because it was still a bit moist. Turned out so delicious! Interesting how something so yummy only needed a few minutes? ???? Thank you for this recipe!

  19. Hey – Thank you for this super easy recipe that really satisfied my craving for something sweet and delicicous! I mixed in a bit of mashed bananas cos I didn’t have enough PB – and it totally worked! Thanks again!

  20. Wow, this was so simple and so good! I was looking for low carb mug cake recipes on pinterest and came across this. I just replaced the sugar with my preferred sweetener. Nice and tasty! I wonder if I could add cocoa for chocolate taste.

Leave a Reply

Your email address will not be published. Required fields are marked *

Recipe Rating