So you’re doing keto and that chocolate craving won’t leave you alone. You don’t want to bake a whole cake. You want one thing: a quick hit of chocolate with a gooey middle that won’t blow your carb count for the day.

Here’s the answer. One mug. One microwave. Done in under 10 minutes. And yeah, it’s got that lava center everyone always talks about (this one actually works, promise).

What This Is (And Isn’t)

This isn’t one of those dry mug cakes that tastes like warm cardboard. It’s soft on the outside and still molten in the middle. Not overly sweet, because keto. But sweet enough to feel like a proper dessert.

You don’t need fancy flour substitutes or weird ingredients you’ll use once and forget in the back of your cupboard. Just simple stuff you probably already have if you’re used to baking keto.

What You’ll Need (All Easy)

Dry Stuff:

2 tbsp almond flour (not almond meal)
1 tbsp unsweetened cocoa powder (dark if you’ve got it)
1.5 tbsp powdered sweetener (erythritol, monk fruit, etc.)
Tiny pinch of salt

Wet Stuff:

1 egg
1 tbsp butter (melted)
1 tbsp heavy cream
1/4 tsp vanilla extract

For the Lava Bit:

1 square (10g) of 90% dark chocolate or keto chocolate bar

Equipment:

1 microwave-safe mug (ideally 10–12 oz)
Fork or small whisk
Spoon
Microwave

How To Do It

Step 1: Melt the Butter

Place the tablespoon of butter directly into your mug.
Microwave for 15–20 seconds until fully melted. Swirl it around the mug to coat the sides lightly. This helps stop the cake from sticking.

Step 2: Add Wet Ingredients

Crack the egg into the mug.
Pour in the heavy cream and vanilla extract.
Grab a fork or mini whisk and beat the wet ingredients together until well combined. It should look like a pale yellow mix.

Step 3: Add Dry Ingredients

Add the almond flour, cocoa powder, sweetener, and salt right into the mug.
Mix well with the same fork. Scrape the bottom and sides to make sure there are no dry pockets left.
Your batter should look like a thick, chocolatey pudding.

Step 4: Add the Lava Center

Take your square of dark chocolate or keto chocolate and press it gently into the middle of the batter.
Don’t push it all the way to the bottom, just enough so it’s halfway submerged and covered with batter on top. This is what creates that gooey middle.

Step 5: Microwave It

Place the mug in the center of your microwave.
Microwave on high power for 45 to 55 seconds.
- Start with 45 seconds if your microwave is powerful (1000W+).
- If it looks too undercooked on the top, go in 5-second bursts.
The edges should look cooked and risen. The middle should still look a little soft and moist. That’s exactly what you want.

Step 6: Let It Rest

Take it out (careful, mug will be hot) and let it sit for 1 full minute.
The chocolate inside keeps melting during this time, and the texture finishes setting.

Step 7: Eat It

Grab a spoon and dig straight in.
You’ll hit the warm cake first, then get to that gooey melted chocolate center.

Optional: top it with a tiny dollop of whipped cream or a dusting of extra cocoa powder if you’re feeling fancy.

Tips For Mug Cake So It Doesn’t Suck

Use a wide mug. If your mug’s too tall and skinny, it cooks unevenly. Wider is better.
Don’t overcook it. If it looks slightly underdone in the middle, that’s perfect. If it’s dry, it’s gone too far.
Chocolate quality matters. Use a decent square of dark chocolate. Some of the “keto” brands taste like chalk. Go 85% or 90% dark if you can’t find a good keto bar.
Microwave strength varies. If your microwave is low power, it might take 60–70 seconds instead of 45–50.
No chocolate square? You can spoon a little unsweetened peanut butter or keto hazelnut spread into the center instead for a different version
Try adding a pinch of instant coffee or cinnamon for a little extra depth.

Carb Count (So You’re Not Guessing)

Here’s a rough breakdown (can vary slightly depending on brands):

Almond flour (2 tbsp): 2g net carbs
Cocoa powder: 1g net carb
Sweetener: 0g net (assuming it’s erythritol or similar)
Egg, butter, cream: basically 0g
Chocolate square: about 2g net (depending on the brand)

Total: ~5g net carbs. Not bad for something that tastes like dessert.

When to Use it

Post-dinner fix. When you’re trying to not snack but… you’re going to snack anyway.
Quick date night dessert. Make two. Call it fancy. Nobody needs to know it came from a microwave.
Meal prep, kinda. Mix the dry stuff in a jar. Then you’ve got your “cake mix” ready. Just add the wet when the craving hits.

Swaps and Switches

Want it dairy-free?

Use coconut cream instead of heavy cream.
Swap butter with coconut oil or avocado oil.

Don’t have almond flour?

You can try coconut flour, but use way less, like 2 teaspoons. It’s super dry.

Want to bulk it up?

Add a tablespoon of chopped walnuts or pecans before microwaving. Adds texture.

What People Mess Up (So You Don’t)

Overmixing. This isn’t cake batter for a wedding. Stir enough to combine and stop.

Using the wrong sweetener. Liquid sweeteners can mess with texture. Stick to powdered if you can. Granular is okay but you might feel a little crunch.

Cooking it too long. Can’t say this enough. The second it goes rubbery, it’s done for. Better to stop early and microwave for another 5–10 seconds than ruin it.

Taste Test Feedback for Keto Chocolate Lava Mug Cake

“I didn’t expect much because mug cakes are usually dry. But this one’s actually moist and gooey in the middle. Even my non-keto kid liked it.” – Jordan, who’s tried 7 mug cake recipes this month

“I added peanut butter instead of the chocolate square in the middle. Unreal. Tastes like a Reese’s, but without the sugar crash.” – Amanda, who lives off peanut butter

“I made it with coconut flour by accident. Still worked. Bit more dense, but still did the job.” – Sam, who doesn’t read instructions

Conclusion

If you’re trying to stay low-carb and want chocolate right now, this recipe works. No weird taste, no long prep, no oven. You don’t even need to put on pants.

Try it once and you’ll probably memorize it. It’s that simple.

Want to turn it into a Pinterest pin? Snap a photo, post it with: “5-Minute Keto Lava Mug Cake That’s Not Dry for Once.”

And that’s the truth.