This sugar free peanut butter fudge is one of my favorite low carb and keto treats because it tastes rich and creamy but only takes about 15 minutes of hands-on time. Everything is made in the microwave, it's essentially fool proof and great for beginners!
One reader told me that our low carb sugar free fudge tastes just like the center of a Reese's cup, and I have to agree that the peanut butter flavor is definitely the star here.
If you love easy lower sugar treats, you might also like our chocolate peanut butter cottage cheese fudge, which adds a higher protein spin, our sugar free ingredient peanut butter cookies or our chocolate covered almonds.
Things to Know About Sugar Free Peanut Butter Fudge
- This is made in the microwave! The fudge mixture cooks for about 5 minutes in the microwave, with stirring every 2 minutes.
- No candy thermometer is needed!
- These have a dreamy soft and creamy texture. Heavy whipping cream and peanut butter keep the fudge rich rather than dry or crumbly.
- We use monk fruit as the sweetener to make this a low carb keto friendly recipe too. Allulose is a great alternative.
- The fudge stores well in both the refrigerator and freezer, so it's perfect for making ahead.
Grab our FREE 150 no carb foods list here OR Snag our Keto Binder HERE!
Ingredients You'll Need
See the recipe card below for exact quantities.
- Butter salted or unsalted works fine
- Heavy whipping cream
- Creamy unsweetened peanut butter - Look for peanut butter without added sugar. A smooth, creamy peanut butter like sugar free Jif works best and tastes the most like sweetened PB.
- Golden monk fruit - This is our preferred low carb sweetener. Erythritol or allulose will also work.
- Vanilla extract
- Powdered monk fruit - Sift this before using it to reduce clumps.
How to Make Keto Peanut Butter Fudge
Step 1: Prep the pan and sweetener
Line an 8x8 or 9x9-inch pan with parchment paper and lightly coat it with cooking spray.
Melt the butter in a medium microwave-safe bowl. Sift the powdered sweetener to remove any lumps.
Step 2: Microwave the cream mixture
Add the heavy whipping cream and golden monk fruit or erythritol to the melted butter and stir.
Microwave for about 5 minutes total, stopping to stir every 2 minutes. The mixture should start to thicken slightly, bubble, and turn a golden caramel color.
Watch it closely toward the end. If you start to smell the mixture burning, remove it immediately.
Step 3: Add the peanut butter
Stir in the peanut butter and vanilla until the mixture is completely smooth.
Add the sifted powdered sweetener and stir until well combined.
Step 4: Chill until firm
Spread the fudge evenly in the prepared pan.
Refrigerate until completely firm before cutting into squares. You can cut it into 16 larger pieces or smaller bite-size pieces depending on how you plan to serve it. You can see both sizes in the photo below.
Recipe Tips
- Don't overcook the microwave mixture. In my microwave, about 5 minutes is the sweet spot. You're looking for a bubbling mixture that has turned a rich golden brown, not one that smells burnt.
- Stir every 2 minutes. This helps the butter, cream, and sweetener cook evenly and gives you more control over the caramelization.
- Sift the powdered sweetener. This is one of the easiest ways to prevent visible white clumps in the finished fudge.
- Monk fruit is my preference. I've tested both monk fruit and erythritol. I prefer monk fruit because it tends to leave less of the cooling aftertaste some sugar alcohol sweeteners can have.
- Let it chill completely before slicing. The fudge will be much easier to cut cleanly once it has fully set.
Substitutions and Variations
Try a different nut butter. Unsweetened almond butter should work in place of peanut butter and is another low carb option. Cashew butter, sunflower seed butter, and macadamia nut butter should also work, but I haven't personally tested these nut variets.
Chocolate topping. A reader told me she loves this fudge with melted chocolate on top and said it tastes like a Reese's cup. A thin layer or drizzle of sugar-free chocolate would be an easy variation.
Meal Prep and Storage
- Sugar free peanut butter fudge is a great make-ahead dessert because it keeps well after chilling.
- Store the fudge in an airtight container in the refrigerator. It will keep well for at least a couple of weeks when tightly covered.
- You can also freeze the fudge for up to 3 months. Place parchment between layers so the pieces don't stick together, then thaw individual pieces in the refrigerator before serving.
Nutrition and Macros
For 16 servings, each piece has approximately:
- 134 calories
- 4g protein
- 12g fat
- 4g total carbs
- 1g fiber
- 3g net carbs
The exact carb count will vary depending on the peanut butter and sugar-free sweetener brands you use.
FAQs
Can you make fudge without sugar?
Yes. This sugar free peanut butter fudge uses monk fruit or erythritol in place of traditional granulated and powdered sugar. Using both a golden and powdered sugar substitute gives the fudge sweetness while keeping the recipe low carb.
Can you make peanut butter fudge in the microwave?
Yes. This recipe is specifically designed as microwave peanut butter fudge. The butter, cream, and sweetener mixture cooks for about 5 minutes before you stir in the peanut butter and powdered sweetener.
Do I need a candy thermometer to make peanut butter fudge?
No. You don't need a candy thermometer for this recipe. Watch for the microwave mixture to thicken slightly, bubble, and turn a golden caramel color instead.
Why is my sugar free fudge grainy?
A granulated or clumpy sweetener can make sugar free fudge feel grainy. Use powdered sweetener in the final mixture and sift it before adding it for the smoothest texture.
Is sugar free peanut butter fudge keto-friendly?
It can be. Use unsweetened peanut butter plus a keto-friendly monk fruit or erythritol sweetener, and check the nutrition labels for the specific brands you use.
More Low Carb Sugar Free Desserts
- Keto Rum Balls
- Low Carb blondies
- Sugar free chocolate covered strawberries
- Keto chocolate mints
- Best sugar free desserts (25+ ideas)
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Recipe
Easy Sugar Free Peanut Butter Fudge (Microwave Recipe)
Equipment
- 1 8x8 square pan or 9x9 size
Ingredients
- 2 oz butter melted
- ¼ cup heavy whipping cream
- 1 cup peanut butter creamy and unsweetened
- ½ cup golden monk fruit
- 1 teaspoon vanilla
- ½ cup powdered monk fruit
Instructions
- Line an 8x8 or 9x9 pan with parchment paper and coat it with cooking spray.
- Prep the ingredients by melting the butter and sifting the powdered monk fruit.
- In a medium-size bowl combine the melted butter, heavy whipping cream, and golden monk fruit. Microwave for about 5 minutes until the mix starts to thicken slightly, stopping the microwave and stirring the mixture every 2 minutes.
- You'll continue cooking the mix in 2-minute increments and stirring after each time until it turns a golden caramel color. Be careful not to overcook because it'll burn.
- Stir in the peanut butter and vanilla until the batter is smooth in texture. Mix in sifted, powdered monk fruit.
- Spread the fudge into an even layer in the pan. Refrigerate the fudge until it's firm before cutting into squares.
- Makes 16 large squares, or it can be cut into even smaller pieces. It'll keep for weeks in the fridge or a few months in the freezer. Enjoy!
Notes
- Cook the butter and golden sweetener mixture for about 5 minutes, stirring every 2 minutes, until bubbling and deep golden brown. Remove it immediately if it starts to smell burnt.
- Sift the powdered sweetener to prevent white clumps in the fudge.
- Unsweetened almond butter, cashew butter, and macedemia nut butter should also work, but we have not tested this variation.
Nutrition
Marlene says
Ok, I have to tell you what I did. I have made these several times and they are always amazing! This last time, however, I messed up somehow. I think I added everything except powdered sugar into the bowl and into the microwave. Cooked it for a bit then realized what I did. I finished it anyway and put it in the fridge. Funny thing is - my husband liked these even better and wants me to make them the same. So I need to try to remember exactly how I did it! (Personally, I like the original better, with melted chocolate on top - tastes EXACTLY like a Reese’s Cup !!). So, even if you make a mistake it will still be delicious!
WholeLottaYum says
I'm glad you both love them, whether they have sweetener or not! This is honestly my favorite low carb treat too. Dipping them in chocolate sounds like an amazing idea. XOXO, Jen
Marlene says
I made this today and it was fantastic! Tasted exactly like the center of a Reese’s cup! And so easy, which is a bonus. This is going on my Christmas baking list for sure!
WholeLottaYum says
I'm glad you loved them Marlene! Happy Holidays! Jen
Jean says
Could you give the recipe amounts in grams for us in the UK. Half a stick of butter means nothing over here🤷♀️
WholeLottaYum says
Updated! Thanks, Jean. The butter amount is 2 oz, I just recently learned that butter sticks sold in many other countries are different than what we buy in the US.
Katie says
Could you use pb2 powder instead of peanut butter?
WholeLottaYum says
Hi Katie, I honestly don't know since I've never tried it that way and I've never had pb2 powder. If you test it please let me know how it turns out! Jen