Keto Peanut Butter Brownie – Rich, Fudgy, and Low-Carb

If you love chocolate and peanut butter but want to stay on track with your low-carb goals, this brownie is a sweet spot. It’s fudgy, rich, and tastes like a bakery treat, minus the sugar crash. You’ll get that classic brownie chew with ribbons of peanut butter throughout.

Best of all, it’s simple to make with everyday keto pantry staples. One bowl, a handful of ingredients, and your oven does the rest.

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Keto Peanut Butter Brownie – Rich, Fudgy, and Low-Carb

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Prep Time 15 minutes mins

Cook Time 30 minutes mins

Total Time 45 minutes mins

Servings: 4 servings

Ingredients Method

Ingredients

  

• 1/2 cup (115 g) unsalted butter, melted (or coconut oil for dairy-free)
• 3 oz (85 g) sugar-free dark chocolate, chopped
• 2/3 cup granulated erythritol or allulose (or your preferred keto sweetener, to taste)
• 2 large eggs, room temperature
• 1 tsp vanilla extract
• 3/4 cup (75 g) fine almond flour
• 2 tbsp unsweetened cocoa powder
• 1/2 tsp baking powder
• 1/4 tsp fine sea salt
• 1/3 cup creamy natural peanut butter (no added sugar)
• Optional: 1/4 cup sugar-free chocolate chips, flaky salt for topping

Method

 

1. Prep your pan and oven. Preheat the oven to 350°F (175°C). Line an 8×8-inch pan with parchment, letting some hang over the sides for easy lifting.
2. Melt the butter and chocolate. In a heat-safe bowl, melt the butter and chopped chocolate together in short microwave bursts (or over a double boiler). Stir until smooth. Let it cool for 2–3 minutes so it doesn’t scramble the eggs.
3. Whisk in sweetener. Add the erythritol or allulose and whisk until glossy. This helps dissolve the sweetener and gives a shinier top.
4. Add eggs and vanilla. Whisk in the eggs one at a time, then the vanilla. Mix just until combined. The batter should look thick and shiny.
5. Combine dry ingredients. In a separate bowl, whisk the almond flour, cocoa powder, baking powder, and salt. Break up any clumps for a smooth batter.
6. Bring it together. Fold the dry mixture into the wet mixture with a spatula. Stir until no streaks remain. If using chocolate chips, fold them in now.
7. Swirl the peanut butter. Pour the batter into the lined pan and smooth the top. Warm the peanut butter slightly so it’s pourable. Dollop it over the batter in spoonfuls and use a knife or skewer to create swirls. Don’t overmix—distinct ribbons look and taste best.
8. Bake. Bake for 18–24 minutes, depending on your oven. The center should be just set with a slight jiggle, and a toothpick should come out with moist crumbs (not wet batter). Slightly underbaked is better for fudgy brownies.
9. Cool completely. Let the pan cool on a rack. For the cleanest slices and dense texture, chill for 30–60 minutes before cutting.
10. Slice and serve. Lift out with the parchment and cut into 12 squares. Sprinkle with flaky salt if you like.

What Makes This Special

This brownie isn’t a “diet” dessert—it’s a real-deal treat with smart swaps. Almond flour keeps it low-carb and grain-free without sacrificing texture.

A blend of cocoa and sugar-free chocolate gives bold chocolate flavor. And creamy peanut butter adds richness and a salty-sweet swirl that makes each bite feel decadent. It’s the kind of recipe that works for weeknights, potlucks, or when you need something impressive without the hassle.

Ingredients

• 1/2 cup (115 g) unsalted butter, melted (or coconut oil for dairy-free)
• 3 oz (85 g) sugar-free dark chocolate, chopped
• 2/3 cup granulated erythritol or allulose (or your preferred keto sweetener, to taste)
• 2 large eggs, room temperature
• 1 tsp vanilla extract
• 3/4 cup (75 g) fine almond flour
• 2 tbsp unsweetened cocoa powder
• 1/2 tsp baking powder
• 1/4 tsp fine sea salt
• 1/3 cup creamy natural peanut butter (no added sugar)
• Optional: 1/4 cup sugar-free chocolate chips, flaky salt for topping

Instructions

1. Prep your pan and oven. Preheat the oven to 350°F (175°C).
   

   Line an 8×8-inch pan with parchment, letting some hang over the sides for easy lifting.

2. Melt the butter and chocolate. In a heat-safe bowl, melt the butter and chopped chocolate together in short microwave bursts (or over a double boiler). Stir until smooth. Let it cool for 2–3 minutes so it doesn’t scramble the eggs.
3. Whisk in sweetener. Add the erythritol or allulose and whisk until glossy.
   

   This helps dissolve the sweetener and gives a shinier top.

4. Add eggs and vanilla. Whisk in the eggs one at a time, then the vanilla. Mix just until combined. The batter should look thick and shiny.
5. Combine dry ingredients. In a separate bowl, whisk the almond flour, cocoa powder, baking powder, and salt.
   

   Break up any clumps for a smooth batter.

6. Bring it together. Fold the dry mixture into the wet mixture with a spatula. Stir until no streaks remain. If using chocolate chips, fold them in now.
7. Swirl the peanut butter. Pour the batter into the lined pan and smooth the top.
   

   Warm the peanut butter slightly so it’s pourable. Dollop it over the batter in spoonfuls and use a knife or skewer to create swirls. Don’t overmix—distinct ribbons look and taste best.

8. Bake. Bake for 18–24 minutes, depending on your oven.
   

   The center should be just set with a slight jiggle, and a toothpick should come out with moist crumbs (not wet batter). Slightly underbaked is better for fudgy brownies.

9. Cool completely. Let the pan cool on a rack. For the cleanest slices and dense texture, chill for 30–60 minutes before cutting.
10. Slice and serve. Lift out with the parchment and cut into 12 squares.
    

    Sprinkle with flaky salt if you like.

Keeping It Fresh

Brownies keep well in an airtight container at room temperature for up to 3 days. If your kitchen is warm or humid, refrigerate to maintain texture.

• Room temperature: Soft and fudgy; best for immediate snacking.
• Refrigerated: Denser and chewier; lasts 5–6 days.
• Frozen: Wrap individual squares and freeze up to 2 months. Thaw in the fridge or enjoy slightly frozen for an ice-cream-bar vibe.

Why This is Good for You

• Low in carbs: Almond flour and sugar-free sweeteners keep net carbs down without sacrificing flavor.
• Higher in fat, moderate protein: Helps support ketosis and keeps you satisfied.
• No refined sugar: Reduces blood sugar spikes and energy crashes.
• Peanut butter perks: Adds healthy fats and a dose of plant protein.

What Not to Do

• Don’t overbake. Dry brownies happen fast.
  

  Pull them when the center is just set.

• Don’t skip cooling. Warm brownies crumble and can taste grainy before they set.
• Don’t use regular peanut butter with added sugar. It bumps up carbs and can make the batter too sweet.
• Don’t overmix the batter. Overmixing can make brownies cakey and dense in the wrong way.
• Don’t swap almond flour 1:1 with coconut flour. Coconut flour is far more absorbent and will dry out the brownies.

Alternatives

• Nut-free: Use sunflower seed butter instead of peanut butter and swap almond flour for a fine sesame flour blend. Expect a slightly different flavor and green tint from sunflower seeds (it’s harmless).
• Dairy-free: Replace butter with refined coconut oil and use dairy-free sugar-free chocolate.
• Different nut butters: Almond butter or cashew butter both work well. Choose unsweetened, smooth varieties.
• Extra-chocolatey: Add 1–2 tbsp more cocoa and a handful of sugar-free chocolate chips.
• Coffee kick: Stir 1 tsp instant espresso powder into the batter to deepen the chocolate flavor.
• Sweetener swaps: Allulose gives the chewiest, least cooling effect.
  

  Erythritol is sweeter but can crystallize slightly; a blend often works best.

FAQ

How many carbs are in each brownie?

It varies by brand and slice size, but for 12 squares, expect roughly 3–4g net carbs per brownie using almond flour, allulose or erythritol, sugar-free chocolate, and natural peanut butter. Always calculate with your specific ingredients.

Can I make this without eggs?

You can try two flax eggs (2 tbsp ground flax + 5 tbsp water) in place of the eggs. The texture will be a bit denser and less glossy, but still tasty and fudgy.

Why did my brownies turn out gritty?

Some sweeteners, especially straight erythritol, can recrystallize.

To avoid this, whisk the sweetener into the warm chocolate-butter mix, or use allulose or a blend. Cooling completely also helps the texture settle.

Do I need to use baking powder?

A small amount helps lift the batter slightly without making it cakey. You can omit it for an ultra-dense brownie, but the texture will be heavier.

Can I use coconut flour instead of almond flour?

Not directly.

Coconut flour is very absorbent and needs more liquid and eggs. If you must use it, follow a recipe formulated for coconut flour brownies.

What kind of peanut butter is best?

Use creamy, natural peanut butter with only peanuts and salt. If it’s very thick, warm it briefly to make swirling easier.

How do I know when they’re done?

Look for set edges and a center that’s just barely firm.

A toothpick should come out with moist crumbs. If it’s clean, they’re likely overbaked.

Can I double the recipe?

Yes. Bake in a 9×13-inch pan and add a few minutes to the bake time.

Watch closely near the end to keep them fudgy.

In Conclusion

Keto Peanut Butter Brownies deliver everything you want in a dessert—rich chocolate, creamy peanut butter, and a fudgy bite—without going off plan. The ingredients are simple, the method is reliable, and the flavor is big. Keep a batch on hand for weeknight treats, quick desserts, or a satisfying snack that won’t derail your macros. Once you try them, they’ll earn a permanent spot in your low-carb rotation.