A 5-Minute Molten Chocolate Mug Cake That's Actually Delicious

Sometimes you have the desire for a homemade cake, but not one shred of desire to turn on the oven, grease cake pans, and pull out the stand mixer to make batter. Sometimes there's no one else around and it's only yourself you've got to please. Sometimes you just want cake now—like within the next five minutes.

This molten chocolate mug cake is designed for those “must have cake now” moments in life: Toss some flour, cocoa, baking powder, sugar, butter, and chocolate into a mug (a 12-ounce microwave-safe one please), stir it up, zap it in the microwave, and you've got a warm and gooey single serving of chocolatey cake waiting to be devoured. 

Don't turn up your nose at the microwave for baking a cake. Cooking with a microwave may not feel as fancy as firing up your conventional oven to make dessert, but these little boxes can be handy when you're short on time (or, let’s be honest, motivation). As discussed in our article on how microwaves work, the appliances operate by firing electromagnetic radiation at your food. These waves effectively target the food's internal water molecules, agitating them at a rate that produces enough friction to generate heat and evaporate water. 

The problem is that the waves can’t penetrate much deeper than about an inch or two into food. What’s more, microwaves hit foods in an unpredictable pattern, so some parts will cook faster than others. Microwave ovens use turntables to help even out cooking to some degree, but another way to help even cooking is to just cook in smaller portions to ensure the heat penetrates through.

This warm and fudgy chocolate cake with a molten center is just the kind of dessert that's perfectly adaptable to the microwave. It doesn’t need the benefits of oven-baking: It’s not supposed to be browned or crispy at the edges, it's not meant to be flipped out of a pan and portioned into perfect slices. It's meant to be enjoyed warm by the spoonful—like a mini soufflé or an oven-baked chocolate lava cake. It won’t have the same perfect fluffy tender crumb structure that an oven-baked cake would—it’s intended to be soft, moist, plush, and molten, which a microwave can do very well.

As the cake cooks in the microwave it bubbles and puffs just as it would in the oven, and just as it starts to set (it'll still be jiggly), it's done—in a mere two minutes. For this fudgy version with a molten center, microwaving the cake at 50% power keeps it moist and tender, and tucking a few pieces of chocolate inside partway through creates its ooey-gooey center.

This cake is so simple to prepare that you could even double the recipe and microwave two mugs at once for a quick, warm, à la minute dessert for two. Top it off with a dollop of whipped cream or a scoop of ice cream. Maybe my favorite part of the recipe is that it requires almost no equipment to prep—just one small bowl and one mug. It’s easy to prepare and even easier to clean up, so you can focus on every single chocolatey bite.

In a small bowl, whisk flour, sugar, cocoa, baking powder, and salt together. To a 12-ounce mug, add half of chocolate pieces with butter. Microwave butter and chocolate pieces at 50% power, stirring every 30 seconds, until melted, 1 to 2 minutes. (See notes regarding microwave power below.)

Add flour mixture, egg, and vanilla and using a fork, thoroughly mix until smooth and well combined (being sure to scrape corners of mug).

Microwave cake batter at 50% power until batter has doubled in size, 50 to 70 seconds. 

Press remaining chocolate pieces into center of cake until top of chocolate pieces are flush with top of cake. Microwave cake at 50% power until cake is firm but top is just wet and tacky to the touch, 15 to 30 seconds (cake may rise above edge of mug, but should not overflow). Let cake rest for 2 minutes. Serve.

Special Equipment

12-ounce microwave-safe mug, microwave

Notes

I developed this recipe in a full-size 1,000-watt microwave. If the wattage of your microwave is less than or greater than 1,000 watts, you will need to increase or decrease the cooking times throughout to reach the visual cues. I recommend writing down the cooking time once you've dialed it in for your particular microwave.

I prefer bar chocolate (milk, dark, or bittersweet), as chocolate chips are harder to insert into the cake to form the molten center, but chocolate chips will do in a pinch.

Make-Ahead and Storage

The mug cake is best enjoyed immediately.