The other day my brother told me he is sick of my mug cake posts. I’m not tired of them yet though. Hopefully you aren’t either. I love that they are fast, especially since I haven’t had time to do a lot of baking. And the one serving size is perfect because nothing gets wasted.

I’ve made a flourless nutella mug cake and a flourless chocolate cake. So the other day I decided to try making a flourless peanut butter mug cake.

Surprisingly, the flourless peanut butter mug cake rose quite high when cooking in the microwave. The other flourless cakes were much more dense. It almost looks like a regular peanut butter mug cake, except there’s no flour.

The cake is very moist and is perfect for peanut butter lovers. And as a bonus, I have another gluten free recipe to add to my collection.

If you enjoy mug cakes, you can view my whole mug cake series here.

Print Print Recipe

Flourless Peanut Butter Mug Cake

Yield: 1-2

Prep Time: 5 mins

Cook Time: 1.5 mins

Total Time: 6.5 mins


2 tbsp of peanut butter
1 tbsp sugar
ΒΌ tsp baking powder
1 tbsp heavy cream
1 large egg


1. Mix all ingredients into a mug. Stir with a small whisk or fork.
2. Microwave for about 1 min. Check on the cake. If not done, cook for an additional 15-30 seconds.


27 Responses to “Flourless Peanut Butter Mug Cake”

  1. Rose — March 7, 2012 at 8:03 am

    Ahhh you’re killing me with these mug-recipes! I want to make them so bad… But I don’t have a microwave :( Any way I could make these in the oven? :D

    • Kirbie replied: — March 7th, 2012 @ 10:19 am

      I’m sure it’s possible to make in the oven but I would worry about the mug breaking. Also it would end up taking a lot longer..

  2. Kay — March 7, 2012 at 8:09 am

    You should write a cookbook about mug cakes!!

    • Kirbie replied: — March 7th, 2012 @ 10:18 am

      Hm, I never thought of that. Maybe I will =)

  3. Iris — March 7, 2012 at 3:20 pm

    I’m definitely not tired of them! I plan to use your mug cake recipes if I become an RA next year. ;)

    • Kirbie replied: — March 8th, 2012 @ 9:35 am

      Ooh, yeah they’d be perfect while living in the dorms.

  4. ChrisB — May 16, 2012 at 7:40 am

    Wondering if this would be okay using sunflower butter and no butter??? Allergies to peanuts and dairy…

  5. ChrisB — May 16, 2012 at 7:45 am

    OOPs… I meant *no cream* instead of no butter. LOL

    • Kirbie replied: — May 16th, 2012 @ 8:24 am

      I’m not sure of the answer because I haven’t tried not using cream. Sorry!

  6. Janet — May 19, 2012 at 4:30 am

    Better late than never to have happened on your web site for the mug cakes. The possibilities are endless, a recipe book might be indicated, but the mug cakes are PERFECT for a sweet tooth without going overboard, suits ALL ages.

    • Kirbie replied: — May 21st, 2012 @ 8:43 am

      I’m glad you’re enjoying the mug cake recipes!

  7. June — May 19, 2012 at 7:25 pm

    ChrisB: I will be trying this recipe soon with Almond Milk ( I have an allergy to dairy as well). I will let you guys know how it goes!

  8. Taya — December 5, 2012 at 10:25 pm

    Oooh I wanna make like all of these mug cake recipes, but we’re always missing ingredients. I know what I’m buying with my birthday moneyy.

  9. mary h — December 16, 2012 at 9:00 am

    uggggggg! my friend moze n i tryd this recipe and it ended up tasting like scrambeled eggs-_-

    • Kirbie replied: — December 16th, 2012 @ 9:18 am

      It sounds like you didn’t mix all the ingredients together thoroughly before cooking it. If the egg is completely mixed in with everything else, it wont cook like scrambled eggs

  10. Jeese — April 3, 2013 at 6:08 pm

    I made this tonight with 2% milk because I had no heavy cream on hand. I also used crunchy peanut butter. While it doesn’t look that appealing, the taste is ok. I added a little bit of cocoa and hoped it would be like peanut butter chocolate but its just peanut butter.

    • Kirbie replied: — April 4th, 2013 @ 12:36 am

      Hmm, def try again if you have heavy cream. It definitely makes a difference compared to 2% milk.

  11. Ellie — April 20, 2013 at 1:47 pm

    I fudged around with this (because I never ever ever use heavy cream, so didn’t have any of it on hand T_T) and used melted butter and a splash of milk instead. Came out quite nicely; not sure if it’s how it’s supposed to be like, but I thought it was still delicious hehe.

    • Kirbie replied: — April 21st, 2013 @ 12:26 am

      Glad it was delicious for you. I think your result was probably similar to the original.

  12. Kate — May 28, 2013 at 7:00 am

    I finally found out why this didn’t work well for me- high altitude! It rose really high, almost to the point of spilling over, so I added cocoa powder to make it into more of a batter.

    • Kirbie replied: — May 28th, 2013 @ 12:12 pm

      Oh yeah, high altitude always messes with the baked goods! I guess even for microwave recipes too.

  13. Millie — March 11, 2014 at 1:48 am

    Hey Kirbie, are there any substitutes for heavy cream? Thanks! P.S I will never be bored of mug cakes! I actually made a homemade mug brownie mix and gave it as gifts in a mason jar. So cute!

  14. Rachel Webb — March 30, 2014 at 3:48 pm

    Made this today for dinner… Turned out as more of a sweet peanut butter biscuit. Not sure quite why it turned out that flat as it almost expanded over the rim of my mug. Must have something to do with the eggs not being thoroughly whipped. Will try again, but will whip the eggs separately and slowly add in. On a better note, it was extremely good.

    • Kirbie replied: — March 31st, 2014 @ 8:58 am

      Hmm that is weird. It may be the egg like you suggested. Or maybe you need to check your baking powder? Though if it expanded while cooking it sounds like the baking powder is working right

  15. Tammy Winters — April 20, 2015 at 12:33 pm

    Mine didnt rise to well. maybe i did not use enough baking powder. ended up quite dense . but it’s ok. gonna try again later. just stumbled across mug cakes. love them!

    • Kirbie replied: — April 21st, 2015 @ 12:35 am

      Hmm, I would definitely check your baking powder because this cake should rise quite a lot, especially when it is cooking. Also are you using commercial type pb as opposed to natural/homemade? The natural stuff isn’t as creamy and doesn’t work as well. Also make sure you add an entire large egg. You might also need to cook longer? if your microwave isn’t powerful enough, it may need longer in there. hope this helps!

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