This keto lava cake is a delicious single-serving mug cake with a gooey chocolate center! 5 ingredients, no flour, and cooks up in just one minute! 

I’ve made plenty of keto chocolate desserts over the years (and many made it into my first cookbook!)- think fudgy brownies and flourless chocolate cake– but this keto lava cake might just be the most dangerous of them all- in the best possible way. It’s rich, gooey, and feels completely indulgent, even though it’s low in carbs and sugar-free. 

I first started making it when my partner and I went on a 30-day keto challenge and needed something sweet before bed. I took inspiration from my popular keto mug cake, but adjusted the ratios to be super gooey in the middle while tender on the outside. The best part is that it bakes in under a minute and always melts into a molten chocolate center. 

While I do prefer the microwave (best texture and also super fast), I did test it in the oven, too, so you have options! 

Key Ingredients

Here’s what you’ll need to make this low carb lava cake, plus my kitchen notes. The measurements are in the recipe card.

• Unsweetened cocoa powder. Dutch-processed cocoa powder or, for a richer dessert, dark cocoa powder. Be sure to sift your cocoa first to ensure there are no clumps in it. 
• Granulated sweetener. I’ve recently updated this recipe to reflect new sweeteners that have come on the market, and for this dessert, allulose works best. It dissolves like white sugar and has no bitter or metallic aftertaste.
• Egg. This helps give the mug cake some rise and fluffiness. 
• Milk of choice. I typically use whole milk (least amount of carbs), but unsweetened almond or coconut milk work too.
• Chocolate. I either add a handful of sugar free chocolate chips to the center or a couple of squares of sugar free chocolate. I like Hershey’s sugar free bars or Ghiradelli unsweetened chocolate.

How to make keto lava cake

Step 1- Mix. In a small mixing bowl, whisk together your cocoa powder, sweetener, and egg until smooth.

Step 2- Assemble. Transfer to a greased 6-inch ramekin or mug. Push down the chopped chocolate into the center of the batter.

Step 3- Microwave for 45 seconds. Remove from the microwave and let it sit for one minute before enjoying it.

Arman’s recipe tips

• 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 ready to serve.
• Molten lava cake should be enjoyed fresh. If left too long, it will become spongy. 
• Add other mix-ins. Feel free to fold through some chopped nuts or seeds for some added texture. 

What to serve with sugar free 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! 

More keto chocolate desserts

• Keto chocolate Cake
• Fat Bombs
• Keto chocolate fudge
• Keto chocolate mousse

Originally published October 2020