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Chocolate Mug Cake turns a packet of hot cocoa mix into a warm, gooey, single-serving cake with a molten marshmallow center, all in about one minute in the microwave, and it has saved many a Sunday night dessert emergency in our house when Maddie and Lizzie want something sweet RIGHT NOW. If cozy cocoa desserts are your love language, our hot chocolate dip belongs on your list too.
Six minutes, two mugs, and zero oven time stand between you and warm chocolate cake.
Chocolate Mug Cake Quick Look
- 🕒 Prep Time: 5 minutes
- 🌡️ Cook Time: 1 minute
- ⏳ Total Time: 6 minutes
- 🍽️ Serving: 2 servings
- ⚡ Calories: 343kcal
- 🌶️ Flavor Profile: Warm gooey chocolate cake with a melty marshmallow middle
- ✋ Difficulty: Easy, even quicker than our vanilla mug cake
Quick Answer
Stir together flour, hot cocoa mix, brown sugar, baking powder, and salt, then stir in milk, melted butter, and vanilla until no dry patches remain. Fold in mini chocolate chips and half the marshmallows, divide half the batter between two greased mugs, tuck the remaining marshmallows into the center, and cover with the rest of the batter. Microwave for 1 minute to 1 minute 15 seconds, then top with whipped cream and chocolate sauce.
Jump to:
Why This Recipe Works
Click to see the technique science
- Hot cocoa mix does double duty. It brings the chocolate flavor AND extra sugar and milk powder, which keep the crumb soft instead of rubbery.
- The marshmallow pocket is the magic. Burying marshmallows in the center creates a molten, hot-chocolate-style core as the cake cooks around it.
- Melted butter beats oil. It adds a rich flavor that microwave cakes usually lack.
- A short microwave time is critical. Sixty to seventy-five seconds cooks the cake through while keeping it moist, mug cakes overcook fast.
- Brown sugar keeps it fudgy. Its molasses holds moisture better than white sugar in a fast, high-heat cook.
- Built for exactly two. The recipe fills two mugs, perfect for dessert night without a leftover cake on the counter.
Why You’ll Love This Recipe
- It goes from craving to warm cake in 6 minutes flat.
- The hidden marshmallow center makes it taste like hot chocolate in cake form.
- It uses the same pantry cocoa as our hot cocoa bombs, no special ingredients.
Key Ingredients
Pantry staples and a packet of cocoa build this mug cake.
- Hot cocoa mix: Three tablespoons of your favorite mix bring the chocolate flavor and keep the crumb tender.
- All-purpose flour: Just 6 tablespoons, this is a true single-serving batter.
- Mini chocolate chips: They melt into little fudgy pockets throughout the cake.
- Mini marshmallows: Half go into the batter, half hide in the center for the molten core.
- Milk, butter, and vanilla: The wet team that turns the dry mix into a rich, pourable batter.
See recipe card for exact quantities.
Variations and Substitutions
One mug, endless directions.
- Use peppermint hot cocoa mix and top with crushed candy canes for a holiday version.
- Swap the chocolate chips for peanut butter chips or chopped peanut butter cups.
- Add a spoonful of Nutella to the center along with the marshmallows.
- Top with a scoop of vanilla ice cream for a molten sundae, as decadent as our flourless chocolate cake.
How to Make Chocolate Mug Cake
- In a medium bowl, stir together the flour, hot cocoa mix, brown sugar, baking powder, and salt.
- In a small bowl, stir together the milk, melted butter, and vanilla, then add the wet ingredients to the dry and stir until no dry patches remain.
- Fold in the mini chocolate chips and half of the mini marshmallows.
- Spray two 10 to 12 ounce microwave-safe mugs with cooking spray. Add a quarter of the batter to each mug, make a small pocket in the center, and tuck the remaining marshmallows inside.
- Cover the marshmallows with the remaining batter, smoothing it out, and microwave one mug at a time for 1 minute to 1 minute 15 seconds until cooked through.
- Let the cakes cool slightly, then top with whipped cream, chocolate sauce, sprinkles, and dehydrated marshmallows.
Recipe Tips & Tricks
- Use a 10 to 12 ounce mug. Smaller mugs overflow as the cake rises in the microwave.
- Grease the mug well so the cake releases from the sides and cleanup is easy.
- Do not overcook. Start with 1 minute, the top should look just set. Every microwave is different.
- Bury the marshmallows completely so they melt into a gooey center instead of puffing out the top.
- Microwave one mug at a time for even cooking.
- Eat it warm. Mug cakes are at their absolute best in the first 10 minutes.
Serving Ideas and Suggestions
Serve this mug cake warm, straight from the microwave, with a swirl of whipped cream, a drizzle of chocolate sauce, and a shower of sprinkles.
It is the perfect movie-night dessert next to a mug of our white hot chocolate for the full cocoa experience.
For a dessert bar, set out toppings and let everyone dress their own mug, the same build-your-own fun as our hot cocoa bombs.
Mug cakes do not store well, the texture firms as they cool, so this recipe is sized for two mugs eaten fresh. You can mix the dry ingredients ahead and store them in a jar, then just add the wet ingredients and microwave whenever the craving hits.
Chocolate Mug Cake FAQs
Yes, and it is the best shortcut in the mug cake world. The cocoa mix brings chocolate flavor, sugar, and milk powder in one scoop, which keeps the crumb soft and tender. Any brand works, and flavored mixes like peppermint or salted caramel add a fun twist.
It was microwaved too long. Mug cakes go from perfect to rubbery in about 20 seconds, so start with 1 minute and check, the top should look just set with a slight shine. Also make sure to stir the batter only until combined, overmixing toughens it.
A 10 to 12 ounce microwave-safe mug is ideal. The batter roughly doubles in height as it cooks, so a smaller mug will overflow. Wide, straight-sided mugs cook more evenly than narrow, tall ones.
Absolutely, just fold all the marshmallows into the batter or leave them out entirely. The marshmallow pocket is what gives this cake its molten hot-chocolate center, but the cake itself is rich and fudgy without it.
This recipe already makes two mugs. To scale further, mix a double batch of batter and cook the mugs one at a time, cooking multiple mugs at once leads to uneven results. For a crowd, a small 6 inch cake pan version bakes in the oven at 350 for about 15 minutes.
Use a mug labeled microwave-safe with no metallic paint or trim. Standard ceramic and glass mugs are fine. The mug gets hot during cooking, so use a towel or oven mitt when taking it out and let it rest a minute before digging in.
Made this Chocolate Mug Cake? I would love to hear how it turned out, leave a comment and a star rating below!
Chocolate Mug Cake
Ingredients
- 6 tablespoons all-purpose flour
- 3 tablespoons hot cocoa mix
- 1 tablespoon light brown sugar packed
- ½ teaspoon baking powder
- Pinch of fine sea salt
- ¼ cup milk
- 1 tablespoon unsalted butter melted
- ½ teaspoon vanilla
- 1 ½ tablespoons mini chocolate chips
- ¼ cup mini marshmallows divided
- Whipped cream for garnish
- Chocolate sauce for garnish
- Sprinkles for garnish
- Dehydrated marshmallows for garnish
Instructions
- In a medium-sized bowl, stir together the flour, hot cocoa mix, brown sugar, baking powder, and salt.
- In a small bowl, stir together the milk, melted butter, and vanilla.
- Add the wet ingredients to the dry and stir together until there are no dry patches.
- Fold in the chocolate chips and half of the mini marshmallows.
- Spray 2 10-12 ounce microwave-safe mugs with cooking spray.
- Add ¼ of the cake mix to the bottom of each mug. Spread it out a little to form a little pocket in the center.
- Divide the remaining mini marshmallow between the two mugs and place them into the little pocket you made.
- Add another 1/4th of the batter on top of the marshmallows and smooth it out so they are covered.
- Microwave for 1 minute to 1 minute and 15 seconds until cooked through.
- Let cool slightly then top with whipped cream, chocolate sauce, sprinkles, and dehydrated marshmallows.
Notes
- Use any of your favorite hot cocoa mixes.
- Make sure that you use a 10-12 ounce mug.
- This is really hot right out of the microwave so be careful.
- The toppings are endless, see other topping suggestions above.
- Adding the marshmallows in the center help this cake stay moist.
- This can be cut in half to make a single serving dessert.
Nutrition
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