Easy Sugar Free Keto Peanut Butter Fudge

Three squares of keto peanut butter fudge topped with sugar-free chocolate chips, stacked on a white plate beside a bowl of peanut butter.
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Introduction

Chocolate and peanut butter – a match made in heaven! If you’ve been around the block on this site, you’ve probably seen those words pop up a few times. And honestly, who can blame us? The combo is pure bliss!

Today, we’re all about simplicity. About 20 minutes at the stove is all the hands-on work here – then the pan does the rest of the job on its own, an hour in the freezer followed by at least two hours in the fridge to set firm. So start this one a few hours before you want to serve it, and you’ll have a scrumptious keto peanut butter fudge to share with family and friends – a true keto confectioner in the making! This creamy and rich fudge comes together with heavy whipping cream, peanut butter, and sugar-free chocolate chips. Each bite is simply divine.

If you’ve been missing fudge since going keto, this is the one to try. Six ingredients, one saucepan, and no candy thermometer in sight – the freezer and fridge do the hard part while you get on with your day.

Let’s get cooking!

Key Ingredients

Heavy Whipping Cream

Heavy whipping cream adds creaminess to our keto peanut butter fudge, giving it its melt-in-your-mouth quality. It is low in carbohydrate and high in fat, which is what makes it fit so easily into keto recipes such as this one. That high fat content is also where a lot of the richness comes from, enhancing the overall taste.

Heavy whipping cream also helps in binding the ingredients together. It helps give the peanut butter fudge a solid and firm texture. You want to be able to hold your fudge bar without it immediately melting on your hand after all.

Unsalted Butter

Butter does a lot of things in this recipe:

  • It adds a rich, creamy, buttery flavor to our keto peanut butter fudge, enhancing the overall taste.
  • It contributes to the smooth and creamy texture of the peanut butter fudge. When melted butter combines with the other ingredients, it helps create a luscious and velvety consistency.
  • It helps bind the ingredients together, giving structure and stability to our keto peanut butter fudge recipe.

We’re using unsalted butter to have better control over the saltiness of our keto peanut butter fudge.

Lakanto Powdered Monk Fruit Sweetener

To give our peanut butter fudge its needed sweetness, we’ll be using Lakanto Powdered Monk Fruit Sweetener — a blend of erythritol and monk fruit extract. It measures cup-for-cup like sugar, which is what makes it straightforward to swap into a traditional fudge recipe without reworking the rest of the quantities. We’ll be leaning on it for nearly all the sweetness here, since everything else going into the pot is unsweetened.

We’ll be using the powdered sweetener form in this recipe as it dissolves more easily than the granulated form. It helps in giving our keto peanut butter fudge a smooth texture. It ensures that our peanut butter fudge doesn’t end up with a grainy texture. Using granulated sweetener has the risk of ending up with gritty fudge bars.

Peanut Butter

To act as our fudge’s base, we’ll be using unsweetened natural peanut butter. Look for one with no added sugar and a short ingredient list — peanuts and salt is ideal — because plenty of jars labelled “natural” still include sugar or added oils. That shorter list also tends to give you a richer, more pronounced peanut flavor. Our store-bought brand of choice is Smucker’s, but you could try others. Just check the ingredient label and the nutrition facts.

Keto Peanut Butter Fudge

Prep Time
5 minutes
Cook Time
15 minutes
Additional Time
3 hours
Total Time
3 hours 20 minutes
Yield
10 servings
Course
Dessert
Cuisine
American

Ingredients

All Ingredients

Nutrition Facts

10 servings per recipe
Trans Fat 0g 0% 0g 0%
Total Sugars — —
Allulose 0g 0% 0g 0%

Where you see an em dash: one of the ingredients in this recipe does not publish a figure for that row, so we cannot add one up honestly. We would rather show you nothing there than a zero we cannot stand behind.

About these numbers: We are home cooks, not certified nutritionists. Nutrition is shared as a courtesy and calculated with free online nutrition calculators — we compare a few to get as close as we can — so please treat it as a helpful estimate rather than a guarantee. The brands you buy, any swaps you make, and how generously you portion the recipe will all move these numbers.

Directions

  1. Heat the heavy whipping cream and unsalted butter over medium-high heat.

    Stir the pot occasionally to prevent scorching.

  2. Add in the Sweetener.

    Once the butter has melted, whisk in Lakanto Powdered Monk Fruit Sweetener until it dissolves completely. Continue to stir constantly to ensure that the mixture does not burn.

  3. Add vanilla extract to the pot.

    Continue to cook the mixture down over medium heat until it thickens and begins to turn a bit light brown in color.

  5. Once the mixture begins to thicken and turn a golden-brown color, remove it from heat.

  6. While the mixture is still hot, whisk in the peanut butter.

    Continue mixing until the peanut butter fully combines with the mixture. You should end up with a smooth and creamy mixture.

  7. Prepare to bake.

    Line a loaf pan or square baking dish with parchment paper. Pour the entire peanut butter mixture into the prepared pan. Make sure to spread the peanut butter mixture evenly.

  8. Sprinkle chocolate chips on top of the peanut butter mixture.

  10. Place the pan in the freezer.

    You can let your peanut butter fudge freeze for about an hour. Once frozen, transfer it to the chiller and refrigerate it for at least 2 hours or until it is set and firm.

  11. Serve and Plate.

    Once the keto peanut butter fudge is set and firm, remove it from the fridge. Cut it into ten pieces and serve. Store the remaining keto peanut butter fudge in an airtight container in the refrigerator or freezer. Eat your keto peanut butter fudge bars as is, or sprinkle them with a little sea salt. Enjoy!

Notes

Other Notes

  • You can use other powdered sugar substitutes in this recipe. Powdered erythritol and Swerve measure cup-for-cup like the Lakanto; allulose is noticeably less sweet than sugar, so taste the mixture and adjust before it goes into the pan. Whichever you reach for, use the powdered form — it mixes in easily and keeps your keto peanut butter fudge from turning out grainy.
  • Customize your keto peanut butter fudge by adding chopped peanuts or melted chocolate chips to the batter. You can also use melted dark chocolate if that’s your preference. Stir your additional ingredient into the fudge mixture before pouring it into the loaf pan or baking dish.
  • If you want your keto peanut butter fudge to have a cakey and thicker texture, you can add almond flour, coconut flour, or peanut flour to the batter.
  • If you want a dairy-free option for butter, you can go with coconut oil or dairy-free butter. Coconut oil is a high-fat option that can provide similar richness and creaminess as butter. There might be a slight change in the overall taste of the peanut butter fudge, but it will still be delicious.
  • This recipe calls for refrigerating your keto peanut butter fudge for at least two hours to give it a firmer texture. Chilling it for a longer time will allow it to set and firm up some more. Alternatively, you can have a softer fudge if you leave it at room temperature.
  • Adjust the sweetness of your peanut butter fudge according to your preference. If you prefer it to be sweeter, just increase the amount of powdered sweetener you add to the fudge mixture. Taste the mixture before chilling it, and adjust accordingly.
  • You can introduce more protein into this recipe by whisking protein powder or collagen powder into the mixture while it’s still warm. Start with a small amount — these powders absorb liquid, and too much will leave the fudge dry and chalky rather than creamy.
  • Store any leftover peanut butter fudge in an airtight container in the fridge. It will stay fresh in there for up to a week. If you need to store it for longer, place it in a freezer-safe container in the freezer instead. It will stay good in there for up to three months.

Frequently Asked Questions

Can I use a different nut butter instead of peanut butter?

Yes, you can replace peanut butter with another nut butter in this recipe. This is particularly useful if you have an allergy to peanuts. Almond butter is a great choice for this. It will provide a different flavor profile but it should still result in a tasty and delectable fudge. Make sure to use almond butter that’s sugar-free and doesn’t contain oil to ensure that the recipe remains keto-friendly.

How do I make this keto peanut butter fudge recipe dairy-free?

For the heavy whipping cream, you can substitute it with coconut cream. It’s a dairy-free option that’s also vegan-friendly. It has a 1:1 ratio to heavy whipping cream, making it easier to insert into the recipe. Do note that using coconut cream may result in a different overall flavor profile, but you should still end up with a delicious keto peanut butter fudge.
You can substitute the butter with a nice vegan dairy-free butter. We like this brand and have used this in a vegan peanut butter cheesecake recipe we posted.

Can sugar-free condensed milk or cream cheese replace heavy cream?

They can, but the substitution will affect the overall taste and texture of the keto peanut butter fudge. Using sugar-free condensed milk will give your fudge a sweeter taste and a denser texture compared to using heavy cream. Using cream cheese will add a tangy cheese flavor to your fudge.
When using either of these replacements, it’s important to adjust the other ingredients as necessary.

Can I use homemade peanut butter in this recipe?

Absolutely! Using your homemade peanut butter can ensure that it’s sugar-free. Just ensure that what you have is creamy peanut butter and not a coarse one. You want your keto peanut butter fudge to have a smooth and creamy texture.
To make homemade peanut butter, you’d have to roast your peanuts. Then, you’d have to process them with a food processor or blender. A coffee grinder may work too, but it won’t be as effective or efficient.
Process the peanuts until they reach a smooth and creamy consistency. Make sure to scrape down the sides of the processor or blender as needed. If you want to achieve a smoother texture, adding oil, such as coconut or peanut oil, might help you. Make sure only to add a small amount.

Can I use regular chocolate chips instead of sugar-free ones?

Regular chocolate chips have added sugar, making them unsuitable for a ketogenic diet. To ensure that this recipe stays low carb, it’s recommended that you stick with keto chocolate chips or dark chocolate. If you want peanut butter fudge to have more chocolate flavor, you can incorporate unsweetened cocoa powder into the batter. If you want it to be sweeter, add more Lakanto Monk Fruit Sweetener.

Can I add other ingredients to my keto peanut butter fudge?

Sure you can! Feel free to customize your keto peanut butter fudge. Chopped nuts, coconut flakes, or a pinch of sea salt can go into the batter for more taste, or on top of the poured fudge before it chills. Just take note of the carb content of whatever you add — the nutrition figures on this recipe cover only the ingredients listed above.

Can I use a different extract instead of vanilla extract?

Yes, you can. Almond and coconut extract both work here and will pull the flavor in a different direction. Extracts are potent, so swap in the same 1 teaspoon rather than pouring by eye, and taste the mixture before it goes into the pan. If you try one, let us know in the comments how it turned out.

Wrap Up

Whether you love peanut butter or are just looking for a low-carb sweet fix, this keto peanut butter fudge will serve you well. Its creamy texture and rich flavors make for a great keto dessert cuisine. Each bite delivers a decadent symphony of smooth peanut butter and luscious chocolate. And it does all that in a low-carb package. A serving works out to about 3g of net carbs, so take a piece or two.

So go ahead, don’t be shy. Treat yourself to keto heaven with this keto Peanut Butter Fudge recipe.

As we alluded to in the intro, we are no strangers to peanut butter dessert combinations. If you try this, rate the recipe and let us know your thoughts in the comments below.

This isn’t the first time we’ve used these two ingredients to make a delicious treat. If you’re as crazy about peanut butter and chocolate as we are, try our Low Carb Double Stuffed Peanut Butter Cups — rich, super creamy, and full of keto-friendly flavor.

If you’re on Instagram, share your creation there and use the hashtag #buttertogetherkitchen. Seeing your kitchen creations and how you might have tweaked the recipe to your liking is genuinely exciting.

Happy Baking!

Updated — August 17, 2026: We rewrote the ingredient notes and wrap-up for clarity, added answers about mix-ins and extract swaps, and fixed a broken link to our peanut butter cups recipe.

Correction — August 17, 2026: We corrected two things. Some jars labelled natural peanut butter do contain added sugar, so check the label. And this fudge needs a few hours to chill, not the 30 minutes we previously stated.