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If you’re a peanut butter lover like me, you have to try this sugar-free keto peanut butter fudge recipe. The taste and texture is spot on, you need just a few ingredients, and you won’t be able to tell the difference at all between this and regular old-fashioned peanut butter fudge with powdered sugar.
Nobody likes gritty fudge, so using a keto powdered sweetener is so important! This recipe relies on Besti Powdered Monk Fruit Allulose Blend because it tastes just like sugar, dissolves easily into the fudge base, and clocks in at zero grams net carbs.
Why You’ll Love This Keto Peanut Butter Fudge Recipe
- Sweet peanut butter flavor
- Silky smooth, fudgy texture
- Preps in just 10 minutes
- Only 3 grams net carbs in a large serving (or less than 1 gram for 1-inch squares!)
- Protein-rich snack
Sugar-Free Peanut Butter Fudge Ingredients
This section explains how to choose the best ingredients for peanut butter keto fudge, what each one does in the recipe, and substitution options. For measurements, see the recipe card below.
- Peanut Butter – Make sure it’s salted and has no added sugar (check labels!). Also, for the fudge to set, it’s important that it’s the thick, creamy kind, not the runny kind. Many brands labeled “natural peanut butter” are too runny for this recipe. I like this brand, which is thick and creamy.
- Butter – I prefer grass fed butter for best flavor and nutrition, but you can use any unsalted butter. If you use an unsalted peanut butter, then your butter should be salted instead.
- Besti Powdered Monk Fruit Allulose Blend – Not only does it taste and act like powdered sugar, it also dissolves easily (unlike other keto sweeteners), for a completely smooth fudge texture. If you have to replace this with a different sweetener, make sure it’s powdered, but keep in mind that powdered erythritol based sweeteners (including most other brands of stevia and monk fruit) may crystallize when storing and create a gritty texture.
- Protein Powder – I used collagen (this brand is great!), but any neutral protein powder should work for sugar-free peanut butter fudge. Be sure it’s unsweetened.
- Vanilla Extract – Optional, but recommended for flavor. You can also use different extracts here to change it up.
How To Make Keto Peanut Butter Fudge
This section shows how to make sugar-free peanut butter fudge with step-by-step photos and details about the technique, to help you visualize it. For full instructions, including amounts and temperatures, see the recipe card below.
- Prep the pan. Line an 8×8 pan with parchment paper or wax paper, letting the paper hang over the sides.
- Melt peanut butter and butter. In a large mixing bowl, heat peanut butter and butter in the microwave, or in a sauce pan on the stove over low to medium heat, until melted.
- Mix keto friendly peanut butter fudge. Stir in Besti Monk Fruit Allulose Blend and collagen powder, until smooth. Taste and adjust sweetener to taste. Remove from heat and stir in vanilla.
- Freeze. Pour the mixture into the lined pan and freeze until firm. (You can also chill in the fridge instead, but the fudge will be more soft.)
TIP: Add toppings before chilling if you like. See variation ideas below!
- Slice. Lift the parchment paper out of pan and place fudge onto a cutting board. Slice into squares.
TIP: A warm, wet knife slices more easily.
Run the knife under hot water before slicing, and anytime you notice sticking.
- Double peanut – Sprinkle some chopped peanuts over the top, or fold into the batter.
- Chocolate chip – Fold sugar-free dark chocolate chips into the batter before chilling, or simply sprinkle on top.
- Buckeye – After making the peanut butter layer, make keto chocolate fudge and pour that over the peanut butter before chilling. (You can also make individual keto buckeyes like this instead.)
- White chocolate – Melt 1/2 cup sugar-free white chocolate chips and stir into the fudge batter.
- Maple walnut – Replace 2-3 tablespoons of the peanut butter with keto maple syrup. Add 2-3 more tablespoons of collagen and 1/3 cup chopped walnuts.
- Sea salt – Sprinkle flaky sea salt over the fudge before freezing.
How Many Carbs Are In Peanut Butter Fudge?
Traditional peanut butter fudge has about 16 grams carbs per 1-inch piece. Instead, this sugar-free peanut butter fudge recipe has just 3 grams net carbs in a 2×2-inch piece (that’s 4 times the serving size!). If you cut the fudge into 1-inch pieces, each one will have less than 1 net carb.
Store the sliced keto peanut butter fudge bars in an airtight container in the freezer. Soften on the counter for a few minutes before serving. (They are also okay in the refrigerator, but will be softer and harder to handle.)
More Keto Peanut Butter Dessert Recipes
If you like this low carb peanut butter fudge recipe, you might also like some of these other keto peanut butter recipes:
- Keto Chocolate Peanut Butter Cheesecake
- Chocolate Peanut Butter Fat Bombs
- Keto Peanut Butter Pie
- Sugar-Free Peanut Butter Cups
- Keto Peanut Butter Cookies
Keto Peanut Butter Fudge Recipe
Keto Peanut Butter Fudge Recipe (4 Ingredients)
This sugar-free keto peanut butter fudge recipe is rich, fudgy, and easy to make with just 4 ingredients. Naturally gluten-free, with a dairy-free option.
Recipe VideoTap on the image below to watch the video.
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Tap underlined ingredients to see where to get them. Please turn Safari reader mode OFF to view ingredients.
Tap on the times in the instructions below to start a kitchen timer while you cook.
Combine the peanut butter and butter in a large bowl (if using the microwave) or saucepan (if using the stove). Heat over low heat, stirring a few times, until melted and smooth.
Stir in the sweetener and collagen powder, until smooth. Taste and adjust sweetener if needed. Remove from heat. Stir in vanilla extract.
Spread the mixture into the baking pan. Freeze for 30-45 minutes, until firm.
To slice, lift the parchment paper out of the pan and place on a cutting board. Run a knife under hot water to warm it up, dry, and use it to cut the fudge into squares. Store in the freezer. If desired, soften on the counter for a couple of minutes when serving.
Last Step: Leave A Rating!
Serving size: 1 2×2″ square
This sugar-free peanut butter fudge is very filling. If you want to enjoy it as a bite size treat with fewer carbs and calories, just cut it into smaller squares.
Nutrition facts are provided as a courtesy. Have questions about calculations or why you got a different result? Please see our nutrition policy.
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