Keto Mug Cake
This single-serve keto chocolate mug cake bakes in the microwave in under 5 minutes for just 4g net carbs. Almond flour, cocoa, and a beaten egg create a warm, tender, brownie-like cake you can have on the table in 7 minutes flat — no oven, no fuss, no sugar.
Head of Nutrition · June 17, 2026
Nutrition per serving
Per serving · makes 1. Values are estimates; brands vary.
This keto mug cake is the answer to a late-night chocolate craving — a warm, fudgy, single-serve cake that goes from craving to spoon in about 7 minutes using just a mug and a microwave. At only 4g net carbs, it scratches the dessert itch without knocking you out of ketosis.
Ingredients
- 3 tbsp blanched almond flour
- 1 tbsp unsweetened cocoa powder
- 1 1/2 tbsp powdered erythritol (or monk fruit-erythritol blend)
- 1/4 tsp baking powder
- 1 large egg
- 1 tbsp unsalted butter, melted
- 1 tbsp unsweetened almond milk
- 1/4 tsp pure vanilla extract
- Pinch of fine sea salt
- 1 tbsp sugar-free dark chocolate chips (optional)
Instructions
- 1
In a microwave-safe mug (at least 8 oz), whisk together the almond flour, cocoa powder, powdered erythritol, baking powder, and salt until no lumps remain.
- 2
Add the egg, melted butter, almond milk, and vanilla. Stir vigorously with a fork until you have a smooth, lump-free batter, scraping the bottom and corners of the mug.
- 3
Fold in the sugar-free chocolate chips, if using, reserving a few to scatter on top.
- 4
Microwave on high for 70 to 90 seconds, until the top is set and springs back lightly when touched. Start checking at 70 seconds — microwave powers vary, and overcooking dries it out.
- 5
Let the cake rest for 1 minute (it firms up as it cools), then eat straight from the mug or turn out onto a plate.
Tips & notes
- Microwave wattage matters: a 1000W oven usually needs about 75 seconds, while a weaker microwave may need closer to 90. Pull it the moment the center is just set for the moistest result.
- Use powdered, not granular, sweetener so the crumb stays smooth — granular erythritol can leave a slightly gritty, gravelly texture in such a quick bake.
- Make it vanilla instead of chocolate by swapping the cocoa for 1 extra tablespoon of almond flour and adding a little extra vanilla. Store leftovers (if any) covered in the fridge for up to 2 days.
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Frequently asked questions
- How many carbs are in keto mug cake?
- This single-serve mug cake has just 4g net carbs (9g total carbs minus 5g fiber), plus 415 calories, 12g protein, and 37g fat. The recipe makes 1 serving and the erythritol sweetener does not raise blood sugar.
- Why is my keto mug cake rubbery or dry?
- Both come from overcooking. Almond flour and egg set fast in the microwave, so even 15 extra seconds turns the cake tough and dry. Check it at 70 seconds and stop as soon as the top springs back — it continues cooking as it rests.
- Can I make this keto mug cake dairy-free?
- Yes. Swap the butter for melted coconut oil and use dairy-free sugar-free chocolate chips. The almond milk is already dairy-free, so the cake stays low-carb with a subtle coconut note.
