Keto Peanut Butter Vanilla Swirl Fudge – Creamy, Low-Carb Treat
This is the kind of treat that feels indulgent but still fits your goals. Creamy peanut butter meets a smooth vanilla layer, then gets swirled together for that classic fudge look. It’s rich, satisfying, and sweet without the sugar crash.
You only need a few simple ingredients and about 15 minutes of hands-on time. Keep a batch in the fridge for when cravings hit, or bring it to a gathering and watch it disappear.
Ingredients
Method
- Prep the pan. Line an 8x8-inch pan with parchment, letting the paper hang over the edges for easy lifting. Set aside.
- Make the peanut layer. In a small saucepan over low heat, combine the peanut butter, 4 tablespoons butter, 1 tablespoon coconut oil, half the sweetener, 1 teaspoon vanilla, and a pinch of salt. Stir until smooth and glossy. Taste and adjust sweetness and salt.
- Thicken if needed. If you prefer a firmer fudge, whisk in the almond flour until fully blended. Keep heat low to avoid scorching.
- Pour the base layer. Spread about 2/3 of the peanut mixture into the lined pan. Smooth the top with a spatula.
- Make the vanilla layer. In a clean saucepan over low heat, melt the remaining 2 tablespoons butter with the remaining 1 tablespoon coconut oil. Whisk in heavy cream, the remaining sweetener, and 1 teaspoon vanilla. Stir until the sweetener dissolves and the mixture is silky.
- Layer and swirl. Pour the vanilla mixture evenly over the peanut layer. Spoon the remaining peanut mixture on top in small dollops. Use a butter knife or skewer to gently swirl the two layers together. Don’t overmix—aim for ribbons.
- Chill to set. Refrigerate for 2–3 hours, or until firm enough to slice. For a faster set, freeze for about 45 minutes, then move to the fridge.
- Add finishing touches. Sprinkle with flaky salt before the fudge fully sets if you like a sweet-salty pop.
- Slice and serve. Lift the fudge out using the parchment. Cut into 25–36 small squares. Store as directed below.
Overeating is a pattern. This helps you fix that problem. A quick reset for cravings, snacking, and “I’ll start tomorrow” moments.
Built for busy home cooks who want real-life structure. Simple steps that fit meal prep, family dinners, and late-night snack attacks.
What Makes This Special
This fudge hits that perfect sweet-salty balance, minus the sugar. It’s made with keto-friendly sweetener, healthy fats, and real vanilla for a clean, full flavor.
The swirl looks fancy but is easy to do, so you get dessert that’s both gorgeous and simple. Best of all, each square is rich enough to satisfy with just a small piece.
What You’ll Need
- Peanut butter (natural, unsweetened) – 1 cup, creamy style works best
- Butter – 6 tablespoons, unsalted
- Coconut oil – 2 tablespoons (helps set the fudge and adds silkiness)
- Powdered erythritol or allulose – 1/2 to 3/4 cup, to taste
- Vanilla extract – 2 teaspoons, divided
- Heavy cream – 2 tablespoons (for the vanilla layer)
- Almond flour – 2 tablespoons (optional, for a thicker texture)
- Pinch of fine sea salt – adjust to taste
- Flaky salt – optional, for topping
- 8×8-inch pan lined with parchment paper
Instructions
- Prep the pan. Line an 8×8-inch pan with parchment, letting the paper hang over the edges for easy lifting. Set aside.
- Make the peanut layer. In a small saucepan over low heat, combine the peanut butter, 4 tablespoons butter, 1 tablespoon coconut oil, half the sweetener, 1 teaspoon vanilla, and a pinch of salt.
Stir until smooth and glossy. Taste and adjust sweetness and salt.
- Thicken if needed. If you prefer a firmer fudge, whisk in the almond flour until fully blended. Keep heat low to avoid scorching.
- Pour the base layer. Spread about 2/3 of the peanut mixture into the lined pan.
Smooth the top with a spatula.
- Make the vanilla layer. In a clean saucepan over low heat, melt the remaining 2 tablespoons butter with the remaining 1 tablespoon coconut oil. Whisk in heavy cream, the remaining sweetener, and 1 teaspoon vanilla. Stir until the sweetener dissolves and the mixture is silky.
- Layer and swirl. Pour the vanilla mixture evenly over the peanut layer.
Spoon the remaining peanut mixture on top in small dollops. Use a butter knife or skewer to gently swirl the two layers together. Don’t overmix—aim for ribbons.
- Chill to set. Refrigerate for 2–3 hours, or until firm enough to slice.
For a faster set, freeze for about 45 minutes, then move to the fridge.
- Add finishing touches. Sprinkle with flaky salt before the fudge fully sets if you like a sweet-salty pop.
- Slice and serve. Lift the fudge out using the parchment. Cut into 25–36 small squares. Store as directed below.
How to Store
- Refrigerator: Keep in an airtight container for up to 10 days.
It stays firm and sliceable.
- Freezer: Freeze for up to 3 months. Place parchment between layers to prevent sticking.
- Serving from the freezer: Let sit at room temperature for 5–10 minutes for the best texture.
Benefits of This Recipe
- Keto-friendly: Uses low-carb sweetener and avoids added sugars.
- Quick and easy: Minimal cooking, no oven, simple steps.
- Satisfying fats: Peanut butter, butter, and coconut oil help keep you full.
- Customizable sweetness: Adjust the sweetener to your taste without affecting texture too much.
- Great for meal prep: Makes a large batch you can portion out for the week.
Pitfalls to Watch Out For
- Using sweetened peanut butter: Check the label. Added sugar will bump up the carbs quickly.
- Overheating: High heat can cause separation or a greasy top.
Keep it low and slow.
- Grainy texture: Some sweeteners can feel gritty. Powdered forms dissolve best; allulose is especially smooth.
- Skipping salt: A pinch of salt balances sweetness and deepens flavor. Don’t skip it.
- Over-swirling: Too much mixing turns the layers muddy.
Stop once you see clean ribbons.
Recipe Variations
- Chocolate drizzle: Melt 1/4 cup sugar-free chocolate chips with 1 teaspoon coconut oil and drizzle before chilling.
- Crunchy add-ins: Stir in chopped roasted peanuts or keto-friendly cacao nibs for texture.
- Almond butter twist: Swap peanut butter for almond butter and add a pinch of cinnamon.
- Maple-vanilla vibe: Add 1/2 teaspoon maple extract to the vanilla layer for classic “fudge shop” flair.
- Protein boost: Whisk 1–2 tablespoons unflavored or vanilla whey isolate into the vanilla layer for extra protein. Add a splash more cream if it thickens too much.
- Dairy-free: Replace butter with more coconut oil and use full-fat coconut cream instead of heavy cream.
FAQ
Is peanut butter keto?
Most natural, unsweetened peanut butter fits a keto lifestyle when used in moderation. Check labels and aim for peanuts and salt only, with low net carbs per serving.
Which sweetener works best?
Powdered allulose gives the smoothest, least gritty texture.
Powdered erythritol blends well too, but can be slightly cooling. You can also use a monk fruit–allulose blend.
Can I make it nut-free?
Yes. Use unsweetened sunflower seed butter instead of peanut butter.
The flavor is slightly earthier but still delicious.
Why did my fudge separate or look oily?
It likely got too hot. Keep the heat low, stir gently, and don’t let it simmer. If it separates, take it off the heat and whisk until it comes back together.
How sweet should I make it?
Start lower, taste, and add more as needed.
Keto sweeteners vary in sweetness, so adjust to your preference without overdoing it.
Do I have to use almond flour?
No. It’s optional for a slightly thicker, more traditional fudge bite. If you skip it, the fudge will be a bit softer but still sets well when chilled.
Can I make this ahead for a party?
Definitely.
Make it up to 3 days in advance and keep it chilled. Slice just before serving for clean edges.
How many pieces should this make?
Cut into 25–36 small squares. The fudge is rich, so smaller pieces are satisfying and help with portion control.
Wrapping Up
Keto Peanut Butter Vanilla Swirl Fudge is a simple way to enjoy a classic sweet without the sugar.
With a handful of pantry staples and a quick swirl, you’ll have a dessert that feels special any day of the week. Keep a stash in the fridge or freezer, and you’re always a few minutes away from a creamy, satisfying bite. Enjoy it your way, tweak the sweetness, and try a variation or two to make it your own.
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