Skinny Peanut Butter Swirl Brownies

A skinny option for peanut butter brownies. Super fudgy brownies made without white flour, butter or oil!

peanut butter swirl brownies

Oh my word. Do I have a treat for you guys today.

I honestly think I am dreaming because today not only am I bringing you the fudgiest, richest, softest, chewiest brownie I have EVER eaten,  I am bringing you a fudgy, rich, soft, chewy, and SKINNY brownie swirled with my one true love (sorry, Kevin): peanut butter.

Skinny & brownie in the same title is a tad ironic, but I am telling you friends… you are not dreaming.

overhead image of a jar of peanut butter

As I begin to train for the Baltimore half marathon coming up in 4 months (anyone else out there running that? let’s be friends), I knew I needed a little treat to put some pep into my running step. Preferably something tasting sinfully chocolatey and smothered in peanut butter because, well… why not.

Most brownie recipes call for loads of butter or oil, white flour, excessive amounts of sugar, and 3+ eggs. Hence, their wonderfully decadent + rich taste. These skinny brownies, however, combine much healthier alternatives, making these brownies good enough to call breakfast. Instead of clogging the brownies with butter and oil, which would inevitably slow me down and have me feeling lethargic, I loaded the brownie batter with low fat vanilla greek yogurt. It gives these brownies that unbelievable moist and fudgy taste that I love in my favorite not-so-healthy chocolate brownies.

In fact, these brownies are so rich and fudgy that someone even told me they tasted like straight up chocolate/peanut butter FUDGE! I can’t even believe there is no oil, butter, or flour these.

peanut butter swirl brownies on a cream plate

In addition to the low fat greek yogurt, I used fiber-rich, whole grain oats instead of white flour – whole grain carbs are a perfect way to start your day and/or fuel a workout! The recipe only calls for 1/2 cup of oats which are ground up into a flour. A brownie’s fudginess directly relates to the amount of flour in the recipe. And with only 1/2 cup of ground up oats in the entire recipe, you can imagine the density and fudginess of these babies!

My recipe has white sugar, but you could easily use 1/2 cup of honey instead. Some readers have even used Truvia, a mix of 1/2 cup brown sugar and 1/4 cup honey, or even 1/2 cup sugar and 1/2 cup dates instead of the 1 cup of white sugar. I’ve used coconut sugar instead which works wonderfully too. No matter how you chose to sweeten it, taste the batter to make sure it is sweet enough.

And to put these brownies completely over the top, I threw in a THICK peanut butter swirl because I firmly believe that there is nothing better in this world than chocolate and peanut butter. Peanut butter is full of healthy fats and protein… perfect for shiny hair, glowing skin, and keeps your muscles workin’!

3 images of skinny peanut butter swirl brownies

So today, here is your recipe for what may the BEST brownie you’ll ever taste. AND a brownie you can actually feel good about eating!

See more of my healthy recipes.

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peanut butter swirl brownies

Skinny Peanut Butter Swirl Brownies

  • Author: Sally
  • Prep Time: 10 minutes
  • Total Time: 3 hours, 10 minutes
  • Yield: 12-16 brownies
  • Category: Brownies
  • Method: Baking
  • Cuisine: American


A skinny option for peanut butter brownies. Super fudgy brownies made without white flour, butter or oil!


  • 3/4 cup (185g) creamy peanut butter*
  • 6 ounces low fat or fat free plain or vanilla Greek yogurt
  • 1/4 cup (60ml) milk (I like to use unsweetened almond milk)
  • 1 large egg (or 2 egg whites)
  • 1/4 teaspoon salt
  • 1 teaspoon baking powder
  • 1 cup (200g) granulated sugar or coconut sugar (see note above in post about substitutions)
  • 1/2 cup (41g) unsweetened natural or dutch process cocoa powder
  • 1/2 cup (40g) old-fashioned rolled oats*


  1. Preheat oven to 350°F (177°C). Spray a 8×8 inch pan with non-stick cooking spray. Set aside.
  2. Place all of the ingredients except for the peanut butter into a blender or food processor. (Yes, a blender!) For easier blending, place the liquid ingredients into the blender first. Blend until mix is smooth and oats are ground up. You will have to stop the blender and scrape down the sides a few times.
  3. Pour batter into prepared baking dish. Batter will be thin. Microwave peanut butter for about 30 seconds. Drop melted peanut butter by spoonfuls onto the batter, swirling gently with a knife to create a marbled effect. (Try not to overmix!)
  4. Bake for 20-25 minutes or until brownies begin to pull away from the sides of the pan. Brownies will be extra fudgy, so be sure to wait until COMPLETELY cooled – I stuck mine in the refrigerator for 2 hours, which allowed them to be cut very easily. Cut into squares and enjoy!


  1. Make Ahead & Freezing Instructions: Brownies stay fresh at room temperature for 2 days, and then can be stored in the refrigerator for up to 5 days after that. Brownies freeze well up to 2-3 months.
  2. Peanut Butter: Do not use natural, runny peanut butter or powdered “peanut butter”
  3. Oats: Make sure oats are certified gluten free if gluten intolerant.
  4. Nutrition: Curious about the nutrition facts? Visit a calorie counting website with your specific ingredients/brands to determine!
  5. Adapted from Dashing Dish.


  1. I made these this morning and just tried them for dinner dessert! WOW! These are fabulous! I’m not even done with this batch and I already can’t wait to make them again!

  2. I do not have a blender…do you think a food processor would work?

    1. Yes, a food processor would definitely work. Thanks!

  3. Could you use greek yogurt instead of the low fat yogurt? And instead of oats, could almond flour be used?

    1. Hi Jesse! Yes, you may use greek yogurt instead of low fat yogurt in this recipe. I would suggest using vanilla yogurt as the plain greek yogurt is too tart. I have not tried almond flour, but I assume this would work just fine.

  4. These are truly unbelievable…and so easy to make! It really is hard to believe something low cal/low fat could taste so delicious. The first time I made them they were not overly ‘fudgy’ as you described, but they were still very good. The second time round I baked them a little less and I now know how they are supposed to taste. A…M….A….Z….I….N….G!!! Less baking time made a big difference.

    My 7 yr. old goes crazy over these. I did make a few minor changes. I cut back the sugar to 3/4 c (substituted 1/2 c. with Splenda) and instead sprinkled 1/4 c milk chocolate chips on top of the PB once out of the oven. (I may add into the batter next time round). The PB left very little chocolate exposed on the top, so I actually reduced that to 1/2 c as well.

    A big tall glass of cold milk comes highly recommended with this yummy, fudgy, stick-to-the-roof-of-your-mouth chocolate goodness! Thanks for the great recipe Sally!

  5. These look amazing! I’m definitely trying them ASAP. Do you happen to know if the recipe would still work as well with all-purpose white flour/if it would still be half a cup? If not, that’s fine and I’ll just give it a shot anyway, with a recipe like this, how bad could it possibly turn out?

    1. Hi Rita! Yes, you may use 1/2 cup of all-purpose flour to replace the 1/2 cup of oats.

  6. I’m on a healthy New Year kick but a weakness for me is baked goods so your recipe really got me thinking and after figuring out that a batch cut into 10 would equate to 2 Weight Watchers points, I just HAD to give it a go!!

    I used fat free vanilla yogurt, 1/3 cup Truvia instead of the cup of sugar and unfortunately had to leave out the peanut butter but the brownies were still lovely and moist and also cakey. I won’t lie and say they’re better than their full-fat, full-caloried counterparts but at less than a quarter of the points and for a decent sized piece (I cut the batch into 10), it really does do the trick and keep the cravings at bay. Thank you for sharing!!

    1. Thanks for calculating that Sophie! I’ve never had these without peanut butter. I love the swirl. But it’s lovely to hear that you enjoy them plain! Thank YOU for reporting back – it’s very thoughtful of you!

  7. Melanie Gottlieb says:

    I just made these–I have all the ingredients in my pantry and it took about 5 minutes to whip them up in my blender and they are soo good! I’m excited to have found this site, and plan to link back to this recipe on my blog. 🙂 Keep the healthier tasty treats coming!

    1. Thanks Melanie! I have some healthy stuff coming up in the next few weeks. 🙂 So glad you love them! They are a favorite of mine. 🙂

  8. Thanks for making your recipes especially this one, world-wide friendly. I live in Australia and find your recipes so easy to make. Most of the ingredients we need are already in the pantry. I do have a problem with melting the peanut butter. I’ve tried 2 brands and they don’t seem to melt even after almost 2 mins in the microwave. It still tastes amazing but don’t look as awesome as yours.
    Looking forward to many more simple but so tasty recipes xo

    1. I’m glad you loved these – all the way from Australia! I’m not familiar with Australian brands of PB, but I always use JIF in my recipes. It melts wonderfully.

  9. Your a pure God send !!!! After I go running I always want something sweet …. This is the thing !!!!!!!! Keep up doing what your fabulous at ( Making delish skinny treats ) !!!!!!!!

    1. Thank you very much Madison – and I am the same way you are post-run! Gimme something sweet!

  10. Hi Sally,

    Your brownies look GORGEOUS and your recipe is so healthy! I think I’m in love. Can’t wait to make them tomorrow!

    Just a quick question though, do you have any tips on how to make those beautiful swirls on your brownies? What kind of swirling motion do you use? E.g. moving the knife in lines, curlicues, figure-8s etc.. Thank you! <3

    1. Hi Jacqueline! Makingt he swirls is easy. Just drizzle about 5 parallel lines of peanut butter across the top of the brownie batter. Then, take a toothpick or knife and drag 5 parallel lines going perpendicular to the PB lines. I hope this helps! Enjoy. 🙂

  11. Hi Sally! I’m trying these pb fudge brownies for a first. They look and sound so delicious! Should I spray or grease the pan prior to prevent sticking? And for the 1/2 c unsweetened cocoa powder.. can I substitute the yellow container nesquik cocoa.. Its sweetened but its all I have on hand. Thanks!

    1. Hi Monica – yes, the recipe says to spray the baking pan with nonstick spray. You may use that cocoa, but try reducing the sugar in the recipe a little bit to make up for the added sweetness.

  12. Amanda Harrison says:

    Oh my word! I just baked these brownies! My boys loved them, even my husband loved them, and he doesn’t like chocolate all that much! Thank you thank you thank you for publishing this recipe! This will be my go to chocolate recipe always. I’m so impressed with the ingredients, but I must confess, I ate too many!!! Luckily they are fat free as I have 3 more kgs to loose. I gained them after surgery, but I don’t mind eating too many of these, they are AWESOME!

    1. Hi Amanda! I’m happy these brownies were a hit for you. They definitely aren’t fat free with the peanut butter, but at least it’s a healthier fat for us!

      1. Amanda Harrison says:

        Sally I didn’t add the peanut butter, I knew I would eat way too many so I played it safe! Hahahaha! Had to check those calories.

  13. This recipe is AMAZING. I was so skeptical, but I had everything I needed right in the kitchen so I decided to give them a try. They are a huge hit with everyone that has tried them, I’ve shared the recipe with all my friends! I will tell you that I accidentally added about two extra tablespoons of cocoa powder the second time I made these (a little bit of a spill) and I like them even MORE, so I will be doing that from now on. They tasted a little more milk chocolatey. 🙂

    1. I have to try adding more cocoa to my next batch. Thanks Katy! I’m happy these were a hit.

  14. Just wondering, do you know about how many cups 6 oz of yogurt is?? I only have a big tub of yogurt, and I’m not sure how to measure it out. Maybe about 3/4 cup? Let me know if you have any thoughts 🙂

    1. Yep, 3/4 cup.

  15. Made these tonight with a few substitutions (used 1/2 c honey like you recommended, and an extra spoonful of greek yogurt)

    I’d also like to add that I used all natural peanut butter and it turned out just fine!! I am also a little confused how these are oil free with JIF peanut butter in them?

    All that aside (I am mostly curious where your statements logic is coming from) these brownies sure are AMAZING!!!

    I will make them again.. and again and again I’m sure! Thanks 😀

    1. Hey Lee! So glad you love these brownies. I simply say this recipe has no added oils or butter, like traditional brownie recipes.

  16. Hi Sally!

    If I don’t have a blender, could I sub regular flour for the oats (1/2 cup?) and use a mixer?

    These look amazing!!

    1. Yes, that would be fine!

  17. Hi Sally, I’m so excited to try these, but wondered if you needed to use a blender or if I use quick porridge oats (much finer than whole oats), or wizz the oats up first could I do the rest in a mixing bowl? Or do you need to really blitz the whole recipe to combine it right? It’s only because I have a tiny blender thing and there’s not enough room for the whole recipe in there 🙂 Thank you

    1. Hey Louisa! Just process/pulverize your oats into a fine powder-like consistency. You’ll also want to beat the egg beforehand. Then combine it all by whisking the batter. Enjoy!

  18. Hi Sally! I have some leftover cookie butter that I’d like to try to use up… What do you think of subbing cookie butter for the peanut butter? Too sweet? Clearly they wouldn’t be flourless or gluten free anymore but…I’d like to try the cookie butter chocolate combo because I never have before and I find the cookie butter VERY sweet so I thought the bitterness of the cocoa and maybe a little bit less sugar with this recipe would be good. Let me know what you think! Thanks! 🙂

    1. Jessica, that would be delicious. I love cookie butter and chocolate together. Let me know if you try it out!

  19. Sally!, what a delicious recipe!! I baked this little beauty today and what a great result. No doubt due to the recipe not my baking skills! I substituted the sugar for a quarter cup of agave syrup and it turned out great. Can’t wait to try the healthy cheesecakes next!! Thanks for all the ideas, motivation and gorgeous photography Sally please keep it up!!

  20. I made these last night & can’t get over how good they are! So moist and fugdy. I just recently started reading your blog and now I can’t wait to make all of your “skinny” recipes. Thank you so much!

  21. Hey, I was planning on making these for my friend’s birthday today! I was wondering if it would change the recipe too much if I substitute all purpose flour for oats?

    1. That would be fine, CC. I’ve recently tried it with no problem.

  22. This was a great recipe! You inspired me to experiment even further. I didn’t deviate from your recipe the first time, and then played with it a 2nd time. To give it a more nutritious ‘punch’ I substituted your cup of sugar for a cup of mashed sweet potatoes (precooked), and instead of 1/2 cup of cocoa powder I used 1/2 cup of whey (some could use soy) protein. I also added a 1/4 cup of chia seeds.

    Thanks for the inspiration.

  23. Wow Sally…just wow/ I just got done making these and holy crap! I used 1/2 cup of honey instead of the sugar and you’d never guess that there is no butter or four or sugar in them. They are so incredible! And it is s o hard to feel guilty for eating one since they are made with all natural ingredients! This recipe was one of the most incredible ones that I have ever made and it absolutely made my day. Even my grandmother (who has the biggest sweet tooth on this planet) said they were amazing. So I just wanted to thank you. They were amazing THANK YOU I WILL DEFINITELY MAKE THESE AGAIN! 🙂 You really are the absolute best Sally!

    1. I’m so happy you love these brownies, Rachael! I make them quite often. My fiancé never can tell the difference between these and my butter-laden brownies!

  24. These are fantastic! I used 1/2 cup raw sugar and a large ripe banana for sweetness + a handful of 60% cocoa dark chocolate chips. So glad i found this recipe!

    This is a real keeper.

  25. sooooo good!! can’t thank you enough for this recipe. just what i’ve been craving!!

  26. I would LOVE to make these, however, with my nut allergy I would have to use sunflower butter. Would that work or would it be too runny?

    1. That should be fine. Enjoy!

  27. Lealou Belle says:

    I have made these brownies several times now and I have to say they are so incredibly fudgy! I don’t include the peanut butter as I’m having a hard time finding peanut butter which will actually melt in the micro instead of going frothy/mousse like. I have a batch in the oven right now actually, but I’ve substituted Stevia for the sugar as an experiment to see if this recipe can produce truly guilt free brownies!

  28. Hi

    I love me sime chocolate and peanut butter…can I use steel cut oats?

    1. That would be fine. Enjoy!

  29. I just made these brownies in search of a recipe that is healthy and delicious that my whole family would enjoy. I used Skippy All Natural PB, 1/2 cup stevia and about 1/4 cup honey. I loved it(especially the peanut butter!), my 8 year old daughter enjoyed it and my husband (hater of most things “healthy”) liked it and said he could eat them over the full sugar & fat alternative. Successes!

    Thank you!!

  30. I made these tonight and they’re so delicious and fudgy! Your recipes never fail me. I did actually use natural runny peanut butter and it worked just fine and looked exactly like your photos. Also I used steel-cut oats that I ground in my food processor. In case that helps anyone!

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I’m Sally, a cookbook author, photographer, and blogger. My goal is to give you the confidence and knowledge to cook and bake from scratch while providing quality recipes and plenty of pictures. Grab a cookie, take a seat, and have fun exploring! more about Sally