Super creamy and rich, this keto peanut butter fudge recipe is the ultimate low carb and sugar-free treat for peanut butter lovers. It’s so easy to make, with only a few basic ingredients. Only 3g carbs per serving!
I can’t get this easy keto peanut butter fudge out of my mind! I updated the recipe recently and now it’s even better and easier than ever. I gave half of it away to my next door neighbour and I regret that now. Deeply.
At least it’s so easy to make, I can whip up a new batch any old time. And I will, believe me.
I have a number of sugar-free fudge recipes but most of them are chocolate based, like my keto rocky road fudge, or my dairy free keto chocolate fudge. They are wonderful and easy to make, but peanut butter makes a welcome change from all the chocolate.
Simplifying Keto Peanut Butter Fudge
I have to admit that sometimes I have a tendency to make things more complicated than they need to be. And this recipe is a perfect example.
Back when I first made it in 2017, I was attempting to make “old fashioned style” peanut butter fudge. I was trying to avoid the all-too-common low carb trick of adding cream cheese to get a more fudge-like consistency, because I do not enjoy the flavor of cream cheese in my fudge.
Making old fashioned fudge is a much more laborious process wherein you boil milk, sugar, and butter together until they reach the soft ball stage of candy making. Then you add the peanut butter and powdered sugar and beat the mixture for several minutes as it cools and thickens. You have to watch it carefully because it can go from almost liquid to too thick in moments.
It’s not a simple process and it relies on ridiculous amounts of sugar (at least 2 cups) to create the right consistency.
My first iteration of this keto peanut butter fudge mimicked that process, and used 1 ½ cups of sweetener. But keto sweeteners aren’t the same as sugar and don’t produce the same consistency. So I found myself adding some peanut flour to help it set properly. It was good, but more complicated than it needed to be.
Then it hit me that I was already sitting on the perfect peanut butter fudge recipe and had been for years and year. My Keto Peanut Butter Brownies, which I first created in 2013, had a delicious fudge-like topping. Why not simply make a bigger version of that?
A healthier fudge recipe with collagen protein
But never one to leave well enough alone, I still modified this recipe a little and added some keto collagen peptides. I don’t like overly sweet desserts anymore and using some collagen powder allowed me to reduce the powdered sweetener and still end up with an amazing creamy fudge.
Many keto dieters use collagen on a daily basis, for its myriad health benefits. It’s said to be very good for hair, skin, and joint health. It’s also a great source of healthy proteins.
I use the Perfect Keto Salted Caramel Collagen in my mid-morning cappuccino almost every day. It’s so good and makes for extra frothy coffee drinks. I cannot recommend it enough.
For this recipe, however, I used the plain unflavoured collagen, as I wanted the peanut butter to shine through. If you would prefer not to use collagen at all, you can add an additional ¼ cup to ⅓ cup powdered sweetener.
FYI that Perfect Keto offers all of my readers 15% off with code ALLDAY15
Tips for making Keto Peanut Butter Fudge
This keto fudge recipe is so simple and whips up in about 10 minutes. Here are my best tips for getting it right:
Line your loaf pan
This is a requirement if you want to get your fudge out in nice pieces. You can use waxed paper or parchment paper. Really press it into the corners and have overhanging edges so you can lift the whole batch of fudge out easily before cutting.
Use creamy peanut butter
There are a number of good all natural peanut butters on the market now that are nice and creamy. The creamier the peanut butter, the creamier your fudge will be.
If your peanut butter that has a lot of oil at the top, try to get as little of the oil into the mix as possible, as it can throw off the consistency and make the fudge too soft. A no-stir peanut butter is definitely a better option.
Salted or unsalted butter?
I personally use salted butter because I enjoy it in my sweets and think it brings out flavor. But some people are very sensitive to salt and if you’re one of them, you may want to use unsalted butter.
The powdered sweetener
A powdered sweetener is key to avoiding a gritty texture. Do keep in mind that I only tested this with Swerve and can’t say that it will work that well with other sweeteners. Some may make the mixture too soft and it won’t set properly. Check out my guide on keto sweeteners here for more details.
Collagen powder for consistency
Add collagen powder allows you to reduce the sweetener while still getting a wonderful creamy fudge texture. But if you can’t get any or you prefer not to use it, you can add an additional ¼ cup of powdered sweetener and achieve the same result.
How to store Keto Peanut Butter Fudge
I personally like this fudge best at room temperature and as long as your ingredients are fresh, it can last for up to 4 days in a covered container.
If it will be around longer than that, it’s best to store in the fridge and it should last for several weeks. Store it in a sealed container to avoid the fudge taking on the flavors of other refrigerated items.
Ready to make some easy keto peanut butter fudge? I think you will love it!
Try these other keto peanut butter recipes!
- Keto Peanut Butter Mousse
- Keto Peanut Butter Cookies
- Keto Peanut Butter Mug Cake
- Easy Keto Peanut Butter Cups
- Keto Peanut Butter Granola
- Keto Peanut Butter Chocolate Chip Skillet Cookie
Keto Peanut Butter Fudge
- 1 cup unsweetened creamy peanut butter (add a pinch of salt if it's unsalted)
- ½ cup butter
- ½ teaspoon vanilla extract
- ¾ cup powdered Swerve Sweetener
- ⅓ cup collagen peptides (see notes)
- Line a loaf pan (8x4 inch or 5x9 inch) with waxed paper.
- In a medium saucepan over low heat, combine the peanut butter and butter. Stir until melted, then stir in the vanilla extract.
- Whisk in the sweetener and collagen until well combined and smooth. Pour the mixture into the prepared pan and refrigerate until set, about 1 hour.
- Lift the waxed paper out by the edges and cut the fudge into 15 pieces.
Ellen Ingles says
today has not been a good cooking day, I don’t know if it was the collagen or the peanut butter I used? I usually don’t use collagen, instead I just use the extra sweetener, but today I used the collagen & ended up with a gelatinous gloppy mess. It’s usually so creamy & heavenly.
I also tried the cinnamon swirled breakfast cake baked in oven, it never did set in the middle, after baking 75 minutes. we just ate the ends, they where delicious.
Melba Flournoy Moon says
Just finished making this fudge! OMG! It is delicious! Hubby approved! It is in the fridge chilling now. Can’t wait until it is ready. Thank you for this great recipe and it was so easy. Oh, I doubled it and used the entire jar. More to enjoy.
This fudge is fabulous. My husband doesn’t even care for peanut butter, but is always asking me to make it! I’m wondering whether this and/or your peanut butter eggs can be frozen – I want to work ahead on treats for Easter.
Yes, they should both freeze well!
This fudge is very easy to make and so delicious! One of my favorites to have in the fridge for a sweet treat!
Jill Franks says
This fudge is incredibly delicious. Both is plain peanut butter fudge, and with sugar free chocolate chips added. Amazing!
Jill Franks says
I wanted my fudge thicker, so I doubled this recipe. I also added about 3/4 -1 cup of Lily’s dark chocolate stevia sweetened baking chips, and for the collagen, I have BioTrust Ageless Multi-collagen in vanilla, and I also have Alayna’s multi-collagen in chocolate. I used 1/3 cup of each. Oh my goodness!! This is the most delicious fudge ever! I just have to remind myself that just because it doesn’t have sugar does not mean it doesn’t have a lot of calories!! I am seriously addicted!
Sandra W. says
Peanut Butter Fudge is a weakness. So I was super excited when I found your recipe. I made it last weekend and WOW am I amazed. Wish I could post a picture here.
I made this tonight. Everyone loved it! Even my kids loved it! And I loved that it was super simple to make. I definitely plan on trying your chocolate recipe next!
let me know when you have a butterscotch/caramel/vanilla fudge. or turn yiur caramel sauce into fudge. that’s my favorite and I know you love a challenge. 🤩
Susan Yakus says
Would I be able to use Great Lakes Beef Collagen?
Lorry Norton says
This sounds so good!!! I don’t have Collagen peptides. I do, however, have peanut powder. Could I use that instead?
Rosemary brenner says
A trick. Leave your peanut butter upside so when you open it, the oil is on the other end ‼️‼️
Which peanut butter did you use? I want to make sure I don’t end up with a runny mess!
I really like Santa Cruz https://amzn.to/3NWOmnl
Susan A says
This has become one of our favorite desserts. Thank you for this recipe!!
I had this recipe for awhile and just was lazy …..
well I made it yesterday
wow wow wow wow
amazing awesome and very hard to stop eating
J Ehlers says
The flavor was excellent. Any suggestions to keep it from getting grainy? I followed the recipe with no substitutions.
Mine was never grainy so I am not sure what’s going on. Try making sure your peanut butter and butter aren’t too hot when you add the sweetener.
I used macadamia nut butter and sprinkled the top with keto white chocolate chips- no regrets! It was phenomenal
Stephanie B says
I made this yesterday! Even my picky teenager who avoids my low carb/keto food items liked it! Thank you for all you do!