You can make this warm, rich chocolate cake filled with raspberry jam in just a few minutes using pantry ingredients.

By

Leah Colins

Senior Culinary Editor

Leah is the Senior Culinary Editor at Serious Eats, and was previously a recipe developer and editor with America’s Test Kitchen for almost 9 years. She has developed recipes for and edited over 20 cookbooks ranging in topic from bread baking to plant-based eating to outdoor grilling and so much more. While there, she also developed recipes and articles for Cooks Illustrated Magazine, Cooks Country Magazine, and ATK’s digital platform.Before her life as a recipe developer, she cooked in 5-star and Michelin-starred fine dining establishments from coast to coast such as The Herbfarm and Aubergine Restaurant at L’Auberge Carmel; she also treasures her time flipping burgers on flattops in her teenage years, and baking and boxing cookies and pies at a wonderful family-owned German bakery in her early professional life.

Published February 03, 2026

Serious Eats / Morgan Hunt Ward, Prop Stylist: Josh Hoggle, Food Stylist: Lauren Jewel

Why It Works

• Using a 12-ounce or larger microwave-safe mug ensures the cake rises without overflowing and making a mess.
• Using 50% microwave power ensures the cake stays moist and tender rather than overcooking.
• Tucking a few pieces of chocolate and cold raspberry jam into the cake halfway through baking creates a molten center.

A mug cake is for those moments when you want cake—but not a whole cake. Not a "preheat the oven, butter the pan, wait 45 minutes" cake. You want a warm, spoonable dessert now, ideally with molten chocolate involved and maybe a little fruit for flair. This five-minute molten chocolate raspberry mug cake is exactly that: a rich, intensely chocolatey dessert for two you can make on a whim, with zero leftovers.

This recipe, developed by Isabelle Easter in our Birmingham, Alabama, test kitchen, is for those moments when you want something homemade, but your patience (and energy) run out after stirring the batter with a fork and pressing buttons on the microwave. It’s made with mostly pantry staples, cooked in two mugs, and ready to eat in under 10 minutes—including the all-important resting time that prevents you from burning your mouth.

It may be tempting to side-eye the microwave as a legitimate baking tool, but don’t. Microwaves don’t heat food the way ovens do; instead of surrounding food with hot air, they excite water molecules inside it, generating heat through friction. The result is something closer to steaming than baking—which sounds wrong for cake until you realize that plush, moist, spoonable desserts are exactly where steaming shines. The goal here isn’t a lofty, sliceable cake you’d get from the oven, but one that is intentionally soft and fudgy, designed to be eaten warm with a spoon—a cross between a lava cake and a mini soufflé. To achieve this in under five minutes of cooking time, there are a few key strategies to get right.

Serious Eats / Morgan Hunt Ward, Prop Stylist: Josh Hoggle, Food Stylist: Lauren Jewel

The first strategy is to resist the urge to blast the cake at full power. While it may seem counterintuitive when speed is the goal, microwaving cakes at reduced power—medium, or 50%—ensures a tender, moist crumb and prevents rubbery or dry edges.. With microwaves, lower power doesn’t mean less heat; it actually means the microwave cycles on and off, giving the batter time to absorb that energy more evenly. The result is gentler cooking that better mimics the slow, steady heat transfer of an oven.

Portion size matters when cooking in a microwave, as well. Microwaves can penetrate food by only about an inch or two, which is why smaller portions cook more reliably. Dividing the batter between two roomy 12-ounce mugs keeps each cake shallow enough for the heat to reach the center, while the extra headspace gives the batter room to puff and rise without spilling over and making a mess.

Because microwaves vary widely in wattage, cooking these mug cakes by visual cues is more important than strict timing. This recipe was developed in a full-size 1,000-watt microwave, which is standard but not universal. Higher-wattage microwaves may cook the cakes more quickly; lower-wattage models may need a little extra time. Mug cakes make this easier to adjust on the fly because the batter is fully visible as it cooks, and their short cooking intervals let you stop, check, and continue without overcooking. Look for the batter to have puffed and doubled in size during the first stage, and the surface to be set but still slightly tacky at the end. Once you dial in the timing on your microwave, it’s worth noting it for future mug cakes.

Another key strategy is how—and when—the molten center is added. Instead of burying the fillings in raw batter and hoping for the best, this recipe takes a more controlled approach. The cakes are par-cooked first, just until their structure begins to set. At that point, a spoonful of cold raspberry jam and a few chunks of chocolate are pressed directly into the center.

Serious Eats / Morgan Hunt Ward, Prop Stylist: Josh Hoggle, Food Stylist: Lauren Jewel

Store-bought jam that is already cooked, concentrated, and perfectly balanced with sugar and acid is ideal for creating a molten center without diluting the cake. Raspberry is a classic pairing with chocolate, adding brightness and contrast, but nearly any jam will work: cherry, strawberry, apricot, even orange marmalade. Use what you like or what’s already in the fridge.

Adding the jam cold, along with chocolate cut into larger 1-inch pieces, slows how quickly each heats up once the cake is back in the microwave, ensuring a gooey center rather than one that disappears into the crumb. A brief second burst at medium power finishes baking the surrounding cake while keeping the center soft and spoonable. After a short rest—just long enough for the cakes to settle and finish steaming inside—you’re left with two warm, fudgy chocolate cakes with molten raspberry centers, made quickly and cleanly, without turning on the oven.

Keep Screen Awake

1/4 cup all-purpose flour (1 ounce; 30 g)

1/4 cup (50 g) granulated sugar

2 tablespoons plus 2 teaspoons (16 g) Dutch-process cocoa powder

1/2 teaspoon baking powder

1/8 teaspoon Diamond Crystal kosher salt; for table salt, use half as much by volume

4 tablespoons (56 g) unsalted butter, cut into 6 pieces

2 ounces (56 g) dark chocolate, broken into roughly 1-inch pieces, divided (see notes)

2 large eggs, lightly beaten

2 teaspoons vanilla extract

1/4 cup (60 ml) cold raspberry jam

Fresh raspberries, for garnish

In a small bowl, whisk flour, sugar, cocoa powder, baking powder, and salt together.

Serious Eats / Morgan Hunt Ward, Prop Stylist: Josh Hoggle, Food Stylist: Lauren Jewel 1.

In a medium microwave-safe bowl, microwave butter and 1 ounce of the chocolate on high power, stirring every 30 seconds, until melted, 1 to 2 minutes. (See notes regarding microwave power below.) 1.

Add flour mixture, egg, and vanilla, and using a fork or whisk, thoroughly mix until smooth and well combined. Divide cake batter evenly between two 12-ounce microwave-safe mugs.

Serious Eats / Morgan Hunt Ward, Prop Stylist: Josh Hoggle, Food Stylist: Lauren Jewel 1.

Place mugs on opposite sides of the microwave turntable. Microwave on medium (50%) power until batter has doubled in size, 70 to 90 seconds.

Serious Eats / Morgan Hunt Ward, Prop Stylist: Josh Hoggle, Food Stylist: Lauren Jewel 1.

Spoon 2 tablespoons jam into center of each mug cake. Evenly divide and press remaining 1 ounce chocolate pieces on top of jam and into center until flush with top of each cake.

Serious Eats / Morgan Hunt Ward, Prop Stylist: Josh Hoggle, Food Stylist: Lauren Jewel 1.

Return mugs to opposite sides of turntable; microwave on medium (50%) power until cake is firm but top is just tacky to the touch, 40 to 55 seconds. Let cakes rest for 2 minutes. Garnish with fresh raspberries and/or ice cream and serve.

Serious Eats / Morgan Hunt Ward, Prop Stylist: Josh Hoggle, Food Stylist: Lauren Jewel

Special Equipment

Two 12-ounce microwave-safe mugs, microwave

Notes

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

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

Make-Ahead and Storage

The mug cake is best enjoyed immediately.

Nutrition Facts (per serving)
735	Calories
37g	Fat
88g	Carbs
11g	Protein

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Nutrition Facts Servings: 2 Amount per serving Calories 735 % Daily Value* 37g 48% Saturated Fat 21g 105% 248mg 83% 374mg 16% 88g 32% Dietary Fiber 4g 16% Total Sugars 59g 11g Vitamin C 4mg 18% Calcium 129mg 10% Iron 7mg 39% Potassium 287mg 6% *The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

(Nutrition information is calculated using an ingredient database and should be considered an estimate.)