Keto Lava Cake


5 from 69 votes
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This keto lava cake is a delicious single serving mug cake with a gooey chocolate center! 5 ingredients, no flour, and ready in just one minute! 

keto lava cake

Keto Lava Mug Cake

We love our keto chocolate desserts around here. Our favorites include fudgy brownies, flourless chocolate cake, and this easy keto lava cake. 

I’m the kind of person that has to end their night with something sweet. I literally cannot remember the last time I did not have dessert and it is one habit I don’t see myself breaking anytime soon. With the baking I do, I always seem to have cookies and cake lying around. However, while trying to practice portion control, I’ve been changing things up and making mug cakes.

I’ve been meaning to share a foolproof keto lava mug cake I’ve been enjoying over the last few months. It satisfies the chocolate and dessert cravings, without the carbs or sugar. 

Now, don’t let this keto lava cake fool you- It may look a little bit fancy, but it is SO simple- t literally takes less than a minute to prepare and less than a minute to make.  No sugar, no flour, and no dairy are needed but you’d never tell. The cake is fluffy and moist, and the filling is gooey. It’s full of chocolate flavor, from the cake to the filling. 

I made this for a friend the other day, for an afternoon treat. They could NOT believe that it was sugar free and low carb– It tasted like any delicious chocolate lava cake!

Ingredients to make a keto molten lava cake

  • Unsweetened cocoa powder– Dutch processed cocoa powder or dark cocoa powder. Be sure to sift your cocoa first, to ensure there are no clumps in it. 
  • Granulated sweetener– Either monk fruit sweetener or erythritol. 
  • Egg– Room temperature egg. This helps give the mug cake some rise and fluffiness. 
  • Milk of choice– Keeps the center of the mug cake moist, with tender on the outside. 
  • Chocolate– To give the molten chocolate filling! Use your favorite keto friendly chocolate bar. 

How do you make a keto lava mug cake? 

In a small mixing bowl, whisk together your cocoa powder, sweetener, and egg, until smooth. Transfer to a greased 6-inch ramekin or mug. Push down the chopped chocolate into the center of the batter and microwave for 45 seconds. Remove from the microwave and let sit for one minute, before enjoying it.


Can I bake this in the oven? 

Yes, if you’d like to make this in the oven instead of the microwave, you can easily do so.

Simply prepare the lava cake as directed, but transfer into a greased, oven safe ramekin. Bake at 180C/350F for 5 minutes, or until the top is ‘just done’. 

Tips to make the best keto chocolate lava cake

  • Do not over bake the lava cake. As there is no flour or milk, it can dry up very quickly. Once the top is mostly done, it is cooked.
  • Molten lava cake should be enjoyed fresh. If left too long, it will become spongey. 
  • Be sure to use a chopped up chocolate bar, NOT chocolate chips. The latter will not melt as nicely and firm up quickly.
  • Feel free to fold through some chopped nuts or seeds, for some added texture. 

What to serve with lava cakes

While this lava cake tastes delicious on its own, you can take it up a notch by adding one (or more!) of the following-

  • Powdered sugar– Sprinkle the tops of the lava cake with keto powdered sugar.
  • Ice cream– Serve the warm cake with a scoop of vanilla ice cream or coconut ice cream.
  • Low carb fruit– Enjoy this with some keto friendly fruit, like sliced strawberries or blueberries.
  • Keto Frosting– Take the cake up a notch with some keto frosting. Chocolate or vanilla are my favorites! 

keto lava mug cake

More keto chocolate desserts to try

keto molten lava cake

Keto Lava Mug Cake

5 from 69 votes
This keto lava cake is a delicious low carb mug cake that is tender on the outside, gooey on the inside! 4 ingredients and ready in just ONE minute!
Servings: 1 Lava Cake
Prep: 1 minute
Cook: 1 minute
Total: 2 minutes



  • In a small mixing bowl, add all your ingredients and whisk together, until smooth.
  • Transfer the mixture into a greased mug or ramekin. Gently insert the chopped chocolate into the center of the batter.
  • Microwave for 45 seconds, until the top is just set. Let sit for one minute, before enjoying.


* Chop up your favorite chocolate bar. Add more, for an even gooey chocolate flavor.


Serving: 1lava cakeCalories: 154kcalCarbohydrates: 7gProtein: 8gFat: 10gSodium: 73mgPotassium: 234mgFiber: 4gVitamin A: 270IUCalcium: 42mgIron: 2mgNET CARBS: 3g
Course: Dessert
Cuisine: American
Author: Arman Liew
Tried this recipe?Give us a shout at @thebigmansworld or tag #thebigmansworld!

Arman Liew

I’m a two time cookbook author, photographer, and writer, and passionate about creating easy and healthier recipes. I believe you don’t need to be experienced in the kitchen to make good food using simple ingredients that most importantly, taste delicious.

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5 from 69 votes (62 ratings without comment)

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Recipe Rating


  1. 5 stars
    Amazing! I switched out 1tbsp cocoa powder for 1tbsp almond flour and it was so delicious. This is going to be a new staple for me!

  2. 5 stars
    Love this recipe! I’m on a calorie deficit and this definitely satisfied my sweet tooth… I substituted the chocolate chips with a tbsp of chocolate syrup! It was amazing and the perfect amount for one!

  3. 5 stars
    Unfortunately this just didn’t do it for me. The cakey part of it tasted bitter… Maybe because I used monkfruit? Which was in your recipe, but I wonder if I had used real sugar if it wouldn’t have been as bitter. Anyway, and then the center chocolate part didn’t really taste like the chocolate fudge in a typical lava cake, but just tasted like… melted chocolate chips. I tried mixing it all together when I didn’t like the taste of the unmixed result, and then it just tasted like liquidy chocolate with a few solid chunks in it. I don’t know… it just didn’t do it for me. 🙁

  4. 5 stars
    Really good! Very tasty and quick to put together. I had to add another 20 seconds to the cooking time but might just be due to cooking in a large thick mug