Keto Chocolate Lava Mug Cake

This mug cake is a single serving of chocolate cake made with almond flour, cocoa powder and erythritol, cooked in the microwave in under a minute. Prep takes 5 minutes, so the whole thing is done in about 6 minutes. A small piece of sugar-free dark chocolate stirred into the batter melts into a gooey center.

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The batter is one egg, a few spoonfuls of dry ingredients and a tablespoon of melted butter, all whisked in the mug you cook it in. There is no bowl to wash and no oven to heat.

What Goes in the Mug

• Egg (1 large): binds the batter and gives the cake its structure and moisture.
• Almond flour (2 tablespoons): the low-carb flour. It gives a slightly nutty taste.
• Unsweetened cocoa powder (2 tablespoons): the chocolate flavor, with no added sugar.
• Erythritol (2 tablespoons): or your preferred keto sweetener.
• Butter (1 tablespoon, melted): adds richness and moisture.
• Baking powder (1/4 teaspoon): lifts the cake.
• Vanilla extract (1/4 teaspoon): rounds out the chocolate.
• Sugar-free dark chocolate (1 ounce, chopped): optional, but this is what makes the lava center.

Out of almond flour? Coconut flour can stand in, but it absorbs far more liquid, so use only about 1 tablespoon and add a little more liquid.

Getting the Texture Right

Everything happens in the mug, so you only need a microwave-safe mug, a whisk or fork and measuring spoons. A small spatula helps scrape the sides so no dry cocoa is left behind. Choose a sturdy mug that can take high heat.

Whisk the egg first until it is frothy, which works air into the batter and keeps the cake light. Then add everything else and mix until the batter is smooth. Stir the chopped chocolate into the middle of the batter if you are using it.

Microwave on high for 30 to 60 seconds, and check at 30. The edges should be set while the center stays slightly gooey. Past that point the cake dries out, so start short and add time if you need it. Let it cool for a minute before you eat it, which firms it up enough to hold together.

A few small choices change the result:

• Use a large mug. The batter rises, and a bigger mug keeps it from overflowing.
• Cold or room-temperature ingredients. Cold eggs and butter give a denser cake. Letting them sit out first gives a lighter one.
• A turntable helps. If your microwave has one, the cake cooks more evenly.

Ways to Change It

• Nuts: a tablespoon of chopped walnuts or pecans adds crunch.
• Berries: a few fresh or frozen raspberries or blueberries, stirred in before microwaving.
• Espresso: a pinch of espresso powder deepens the chocolate flavor.
• Mint: a drop of peppermint extract.
• Other sweeteners: monk fruit or stevia can replace the erythritol, and each tastes a little different.
• More chocolate: double the sugar-free dark chocolate for a bigger lava center.

What to Serve With It

A dollop of whipped cream or a scoop of sugar-free vanilla or chocolate ice cream sets off the warm cake. Fresh raspberries or strawberries, unsweetened coconut flakes, chopped nuts or a sprinkle of cinnamon all work as toppings. A drizzle of almond or peanut butter is another option. For a drink, black coffee balances the sweetness, and peppermint or chamomile tea suits a quieter finish.

Nutrition

One mug cake has about 300 calories, 25 grams of fat, 4 grams of carbohydrates and 8 grams of protein, according to the recipe card.

FAQ

Can I use a different sweetener?

Yes. Monk fruit or stevia can replace the erythritol. Adjust the amount to how sweet the one you pick is.

What can replace almond flour?

Use coconut flour, but reduce it to about 1 tablespoon and add a little more liquid, because it absorbs more.

How should leftovers be stored?

Cover the cake and keep it in the fridge for up to two days. Reheat it in the microwave.

What toppings go well on it?

Whipped cream, keto-friendly ice cream, chopped nuts, unsweetened coconut flakes and a pinch of cinnamon all work. The contrast between the warm cake and a cold topping is the main appeal.

Can I make it ahead?

It is best fresh, but you can mix the dry ingredients in a jar in advance. When you are ready, add the wet ingredients and microwave.

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Written and edited by The Foodie Yummy Kitchen Team

The Foodie Yummy Kitchen Team writes and edits the recipes on Foodie Yummy: classic American potluck salads, holiday sides and easy comfort food, with a few low-carb options. Every recipe lists exact quantities, numbered steps and a printable recipe card, plus notes on swaps, storage and make-ahead timing. Spot a problem with a recipe? Tell us through the contact page and we will correct it. About us