This peanut butter keto mug cake takes only minutes to make! It’s tender and lightly sweetened, and makes a wonderful easy breakfast or dessert.
Sometimes I create recipes with a specific outcome in mind. And sometimes I throw together some ingredients on a whim and hope for the best. This keto mug cake recipe falls into the latter category!
But while it was rather slapdash in its creation, it quickly became a fan favorite recipe. And a family favorite too! I often whip these little keto cakes up when we need a quick treat.
You know that I take peanut butter and chocolate very seriously. And many of my recipes are quick and easy, like Keto Peanut Butter Bars and easy Peanut Butter Protein Balls. So you can rest assured that these easy mug cakes are good stuff!
Why you will love this recipe
Mug cakes have appeal because they are so easy to make. But they can also have a bit of an odd texture from the fast cooking method. They tend to end up a bit spongy.
These keto peanut butter mug cakes differ in that regard. There is something about the addition of peanut butter that gives them a proper cake texture. And yet they take only about 5 minutes to make.
They really are super family friendly and since this recipe makes six, you can feed the littles and yourself. You can also scale the recipe back and make only three servings, which is more appropriate for those who live alone or are doing keto alone.
And these easy cakes store quite nicely. I do recommend cooking them all at once, as the batter thickens if it sits too long. But you can store the finished keto mug cakes in fridge and re-warm them easily when you want another serving.
Reader Reviews
“These are the Creme de la Creme of mug cakes….my all time favorite (and I am beginning to be way too familiar with mug cakes). But the peanut butter adds some density so that these are not just fluff on a spoon. There is just the right amount of substance….and the flavor is FABULOUS. Caroline, you are amazing. You obviously put a lot of testing into your recipes because they are the gold standard in my opinion. thank you for putting food worth eating on our low carb table.” — Deborah
“I was skeptical to try this because I am in South Africa and we have limited choice of ingredients. Well, they cam out perfectly and I am so happy I made the effort, thank you! It was so easy to make and I will definitely make it again!”– Linda
“Wow! Easy and delicious ! I’m addicted! I don’t usually like the texture of mug cakes, but these are wonderful. Thanks again for another winner!”– Joan
Ingredients needed
- Peanut butter: I recommend a good natural peanut butter like Santa Cruz. But you can use any nut butter here if you are allergic to peanuts.
- Butter: I like to use salted butter because the salt brings out a little flavor. You can also use coconut oil if you want to be dairy-free.
- Almond flour: As always, the finer your almond flour, the better the texture of your cakes. I have been using Blue Diamond lately and find it works quite well.
- Sweetener: Use your favorite granular sweetener. I really like the flavor that Swerve Brown adds here, but you can also use allulose or BochaSweet.
- Dark chocolate chips: Both ChocZero or Lily’s work nicely in this mug cake recipe. You can also skip the chips to save on a few carbs, if you like.
- Kitchen staples: Eggs, baking powder, and vanilla extract.
Step-by-step directions
1. In a microwave safe bowl, melt the peanut butter and butter together in short bursts, stirring until smooth.
2. In a medium bowl, whisk together the almond flour, sweetener, and baking powder.
3. Stir in the eggs, vanilla extract, peanut butter mixture, and water until well combined. Stir in the chocolate chips.
4. Divide among 6 ramekins or mugs and microwave each for about 1 minute, until puffed and set. Serve warm.
Expert tips
Peanut butter tends to thicken cake batters the longer it sits, so you need to work relatively quickly on this one. Try to get it into the mugs as soon as it’s all mixed together and then cook them straight away.
Several readers have asked if they can prepare the batter and then refrigerate the cakes until they are ready to make them. This doesn’t work well because the batter can thicken and the cakes won’t rise properly. You are better off cooking all of the cakes and then re-warming it when you are ready to eat.
We like to eat them right out of the mugs but if you want to remove them, be sure to grease your mugs or ramekins very well.
Oven Baked Method: If you prefer to make these in your oven, try baking them at 350ºF for 12 to 15 minutes.
Nut-Free Version: You can make these with sunflower butter and sunflower seed flour. But you will want to replace 1 tablespoon of the water with some lemon juice to offset the green reaction that occurs between sunflower seeds and baking powder.
Frequently Asked Questions
Cover extra mug cakes tightly and store at room temperature for 1 day. You can also store them in the refrigerator for up to 5 days. To reheat, place it in the microwave for 15-20 seconds until just warm.
You can also freeze extra mug cakes. Wrap them tightly in plastic wrap or foil and freeze for 3-6 months. If freezing, it is best to remove them from the mug first, then wrap and freeze.
This keto mug cake recipe has 6.7g of carbs and 3g of fiber per serving. That comes to 3.7g net carbs per mug cake.
More keto mug cake recipes
Peanut Butter Keto Mug Cake Recipe
Ingredients
- ⅓ cup peanut butter
- ¼ cup butter
- ⅔ cup almond flour
- ⅓ cup Swerve Sweetener
- 2 teaspoon baking powder
- 2 large eggs
- ½ teaspoon vanilla extract
- ¼ cup water
- 3 tablespoon dark chocolate chips, sugar-free
Instructions
- In a microwave safe bowl, melt the peanut butter and butter together in short bursts, stirring until smooth.
- In a medium bowl, whisk together the almond flour, sweetener, and baking powder.
- Stir in the eggs, vanilla extract, peanut butter mixture, and water until well combined. Stir in the chocolate chips.
- Divide among 6 ramekins or mugs and microwave each for about 1 minute, until puffed and set. Serve warm.
Valorie Matthews says
I use powdered Swerve and it wasn’t sweet as I would of liked it! Was I suppose to use granulated Swerve? Is there a difference? I think I would really like it if it was just a little more sweeter!! Thanks!!
Carolyn says
The kind of Swerve would really make no difference. Just use more…sweetness is a very individual taste.
Anna says
Carolyn or anyone, any ideas why the chocolate chips all ended up on the bottom when I made this?
Carolyn says
Sounds like somehow your batter is too thin. What brand of almond flour are you using?
Anna says
I made it with the King Arthur Flour brand. I usually have Honeyville but was out. The King Arthur seems pretty similar to Honeyville’s. I’ll try to have the batter thicker next time, maybe with a bit more almond flour, and see if that helps.
Sue says
Hi Carolyn,
How long would I bake this if I make it in an 8×8 pan and at what temperature?
Carolyn says
I have not made it that way but I would think that 325 for 15 to 20 would probably be right. Keep an eye on it, you will need to figure out when it’s done.
Anna says
I divided the batter evenly between 4 mugs, microwaved for 1 minute each and they came out fine, except all the chocolate chips sank to the bottom. Is that because I had more in each mug than the recipe calls for? Anyone else have this happen?
Kathleen Johnston says
I just put the chocolate chips on top of cake when it came out of microwave and they melted over the top.
Micaela Hess says
Thanks for the recipe! Where can one find sugar-free chocolate chips?
Carolyn says
Please click the link in the recipe! 🙂
paloma says
Hi! Thank you for the recipe, I would like to know the calories per each muffin, is it 323kcal each? thanks!
Carolyn says
Yes, 323 cal per cake.
sydney says
Made it with splenda and it worked perfectly. The whole family enjoyed it 🙂
Carolyn says
Glad it worked out!
sydney says
Hi I am excited to try this! Could this be made with splenda? I am new to low carb, are we talking liquid or dry sweetener? Thanks!
Carolyn says
I didn’t try this with Splenda, although I think it should work. My sweetener is granulated, what were you planning on using?
sydney says
I was thinking granulated splenda
Carolyn says
Then you should be able to sub that in directly for Swerve. *I think!*
Jessica says
Hi! Recipe sounds great, however I am on keto and you said in the beginning that this was sugar free, however peanut butter has sugar in it…am I missing something? Thanks!
Carolyn says
Not all peanut butter has sugar! Please read your labels…
Darlene says
I also baked this in an 8×8 pan, it was great!
Alisa says
I hadn’t yet found a mug cake recipe I liked, but your recipes have never steered me wrong, so I gave it a shot. Despite realizing that a minute is a little too long for my microwave (the first cake was a bit dry), the flavor was an instant hit and I loved it! I finally settled on 50 seconds (even better I don’t have to wait as long!) and I learned this even tastes good cold leftover from the fridge. Thanks for making a mug cake believer out of me!
Carolyn says
So glad to hear it!
Hollie says
Fantastic recipe!! I ended up baking it in an 8×8 pan. Just wonderful!
Allison Hicks says
This looks AMAZING but I am deathly allergic to almonds. Can I substitute the almond flour for something else?
Carolyn says
Try sunflower seed flour.
Deborah says
These are the Creme de la Creme of mug cakes….my all time favorite (and I am beginning to be way too familiar with mug cakes). But the peanut butter adds some density so that these are not just fluff on a spoon. There is just the right amount of substance….and the flavor is FABULOUS.
Caroline, you are amazing. You obviously put a lot of testing into your recipes because they are the gold standard in my opinion.
thank you for putting food worth eating on our low carb table.
Megan says
This is one of the best, if not THE BEST, low-carb dessert recipe I’ve come across. Fluffy, delicious, and easy to customize. Thanks!
Kathy says
Delicious! Since there are two of us, and to prevent us from having three each at one go, I wrapped two (uncooked) in plastic, refrigerated, and just microwaved them now…yes, we did have two each after dinner…. These were just as good as the ones were last night, and probably better tasting than they would have been cooked yesterday and eaten cold today. Now I am wondering how far ahead I can prepare the batter and just bake as needed?
Lois says
This looks like a great recipe for a dinner we’re hosting next weekend for another couple who are on a low carb diet. Had a question about the peanut butter: would crunchy peanut butter made with just peanuts work? That’s the type our family eats as regular peanut butter contains sugars and hydrogenated oils.
Carolyn says
Yes, that should be great.
anne l says
Hey Caroline, think i could sub out coconut oil for the butter? on a yeast cleanse right now and no butter for 1st 2 weeks.
thanks and we love all your recipes!
Carolyn says
You bet, that would be just fine.
Erin @ The Spiffy Cookie says
I definitely agree. As you get older your brain fills up more and one year is a smaller fraction of your life the longer you life, therefore seeming shorter and shorter. Not cool! But I’ll forget about that once a mug of this appears in front of me.
Tina says
I just tried these and they are delicious! I have one question – what is the gritty taste? I’m thinking it’s the almond flour because of the texture. Thanks.
Carolyn says
Mine are not gritty at all so I wonder what kind of almond flour you are using. Or what kind of sweetener?
Sarah M. says
Are you sure you didn’t use almond meal/flour instead of finely ground?
Karen says
Thank you for another fantastic recipe! Yummy! Your email is the first I open,
Your recipes have kept our lives low carb. Thanks again.
Carolyn says
So glad to hear it!