Kirbie's Cravings

3 Ingredient Peanut Butter Cake (Keto, Low Carb)

This single-serving peanut butter cake is just 3 ingredients and very easy to make. This cake doesn’t require any flour or low carb flour alternatives. The batter takes less than five minutes to prepare and you don’t even need a mixer. This is an easy cake to make when you’re craving something sweet but don’t want to make a full cake.
single-serving peanut butter cake in a yellow ramekin.

If you’re looking for a quick and easy dessert, this is it. I love that it can be eaten warm and served with ice cream, sugar-free syrup, or whipped cream.


  • Egg
  • Peanut Butter
  • Erythritol


  • The egg provides the structure for this cake. I do not know of a substitute for the egg for this recipe.
  • This recipe uses creamy peanut butter. You can use either natural or regular unsweetened peanut butter. Peanut butter can be replaced with almond butter.
  • Erythritol can be substituted with Lankanto monkfruit sweetener or Swerve.

overhead shot of the cake.

Keto Peanut Butter Cake Texture And Flavor

This cake has a very tight crumb, similar to other flourless cakes. It has a strong peanut butter flavor but is not super sweet. It is a little plain to eat on its own, so I recommend serving it with toppings like whipped cream, ice cream, or sugar free syrup.
close-up shot of a spoon scooping some cake.

More Easy Keto Cakes

3 Ingredient Peanut Butter Cake (Keto, Low Carb)

Servings: 1 cake
Prep Time: 5 minutes
Cook Time: 17 minutes
Total Time: 22 minutes
Course: Dessert
Cuisine: American
This single serving cake is so easy to make with just 3 ingredients. It can be served warm with your favorite toppings.
4 from 4 votes


  • 1 large egg
  • 2 tbsp (32 g) creamy peanut butter unsweetened
  • 1.5 tbsp (18 g) erythritol granular


  • Preheat oven to 350°F. Grease the interior of an 8 oz ramekin or similar sized baking dish.
  • Add egg to a medium bowl. Whisk egg vigorously with a whisk for one minute.
  • Add in peanut butter and erythritol. Whisk until completely incorporated and batter is smooth. Pour batter into prepared ramekin.
  • Bake cake for about 16-20 minutes or until cake has risen and when you apply light pressure on the surface it bounces back. Cake should rise above the ramekin during baking but will sink down and shrink once out of the oven. Let cake cool a few minutes before serving. If desired, plate cake in a smaller ramekin or plate. I plated mine in a smaller ramekin. Serve with your favorite toppings like ice cream, whipped cream or sugar-free syrup.


  • If you have questions regarding substitutions, please see substitutions section of the post.
  • This recipe can be made with natural or regular peanut butter. I used natural and found it easier to stir in.
  • The ramekin I used for baking is an 8 oz ramekin that is 3.75 inches wide.
  • I used So Nourished erythritol sweetener granular*
  • *This product link is an affiliate link. This means I earn a small commission from qualifying purchases.
  • If you are on a keto diet, please remember to look at net carbs and not just total carbs. The net carbs count excludes fiber and sugar alcohols (carbs from erythritol).


Serving: 1cake, Calories: 262kcal, Carbohydrates: 25g, Protein: 14g, Fat: 21g, Saturated Fat: 4g, Sodium: 71mg, Fiber: 3g, Sugar: 2g, Carbs from erythritol: 18g, NET CARBS: 4

The nutrition information provided are only estimates based on an online nutritional calculator. I am not a certified nutritionist. Please consult a professional nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.

Did you make this recipe?I'd love to see it! Mention @KirbieCravings and tag #kirbiecravings!

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Recipe Rating

24 comments on “3 Ingredient Peanut Butter Cake (Keto, Low Carb)”

  1. Loved this. Tried the coconut one also and it was amazing. Love your recipes!

  2. Can I use Truvia granular in place of the erythritol granular?

    • We haven’t tried it, but it’s often used as a substitute in other recipes. Let us know how it works for you!

  3. Excellent! Will try with peanut butter powder or unflavored protein powder  next time!

  4. Oh my goooooodness!!!
    Hits the spot every time
    My variation is sugar free chocolate chips on the top in the last few minutes in the oven ? soooo gooood!
    Love the texture!!
    And not too sweet!

  5. Thank you for this awesome recipe! I’ve made it 3x now. I add some vanilla extract, cinnamon, and sometimes cacao powder. It’s a hit! I also add a tbs of cottage cheese to add moisture and some baking powder. I like to pair these muffins with a creamy french vanilla chai tea. Thanks again!

  6. I noticed this is 25 g carbs…is this a misprint?

    • No, it’s not. For keto you always want to look at the net carbs. Hope that helps!

      • No one who is counting carbs on a Keto diet would eat a 25g carb cake! Check AGAIN! 1 egg has .2 carbs and 32g of peanut butter has 7 carbs. 

      • Thanks for your comment – for keto, you should look at net carbs which are four for this recipe. Whether that is “high” or “low” depends on each person’s diet and goals.

  7. Could this be microwaved like a mug cake?

  8. Yummy, quick and easy. Too sweet, would put in less sweetener next time. Used Lakanto maple flavored syrup drizzled on top – total yum. will make again.

  9. I made these yesterday for an after dinner Dessert. I will start with the fact that I don’t follow Keto diet, nor really know what it involves but this recipe sounded interesting. I did use regular confectioners sugar instead of the sugar substitute. I topped the cakes with a chocolate Espresso frosting. it was good, the cake was moist but densen, I attribute that to there no flour or other levening agent.

  10. Hi. Can this be done in the microwave? I hate to heat up my oven for a one-serving cake.