This flourless mug cake is the perfect single-serving chocolate fix when you don’t want to make a full dessert. It requires just one egg, chocolate chips, cocoa powder, sugar, oil and a touch of baking powder. Everything is mixed in one bowl, poured into a mug or ramekin, and microwaved for about one minute. From start to finish it takes only a few minutes to prepare and results in a warm, fudgy cake that’s closer to a molten brownie than the dry, spongy mug cakes you might have tried before. It’s rich, intensely chocolatey, and ideal for satisfying a sudden craving for exactly one portion.
Why This Cake Doesn’t Need Any Flour
This recipe leaves flour out entirely, so there’s no need to substitute or perfect a gluten-free flour blend. The egg provides the structure, much like in larger flourless chocolate desserts, but scaled down for a single serving. The chocolate chips melt into the batter as it cooks, adding moisture and richness while helping bind the cake. Cocoa powder delivers the deep chocolate flavor and a bit of body, the oil keeps the crumb moist, and the small amount of baking powder gives the cake just enough lift to feel like cake rather than a pudding.
One important detail is the microwave time. Whisk the batter until smooth and fully combined, but be careful not to overcook. One minute on high typically produces a set top with a soft, almost molten center. Even an extra 10–15 seconds can turn a fudgy center into a dry one, so watch the timing closely.
The 10-oz. Mug Rule
Use a mug or ramekin that holds at least 10 ounces. The batter rises dramatically while cooking—sometimes two to three times its original height—so a smaller vessel can overflow. Most standard coffee mugs hold 10–12 ounces, but if you’re unsure, fill the mug with water and measure it. A wider, shallower mug or a ceramic ramekin helps the batter cook more evenly than a tall, narrow cup.
Flourless Baking Tips
- Remove at the 1-minute mark, even if the center looks slightly glossy. The residual heat will finish cooking the center and preserve a fudgy texture. If you microwave until it looks fully set, the cake will likely be dry.
- Whisk the egg alone first. Beating the egg briefly before adding the other ingredients prevents bits of uncooked white from clinging to the bottom of the bowl and creating a rubbery spot in the finished cake.
Flourless Mug Cake
Equipment
- 1 10–12 oz. microwave-safe mug or 10 oz. ceramic ramekin
Ingredients
- 1 large egg, beaten
- 2 tbsp (30 g) semi-sweet chocolate chips
- 2 tbsp (10 g) unsweetened cocoa powder
- 1 tbsp (15 g) granulated sugar
- 1 tbsp (15 ml) vegetable oil
- 1/4 tsp (1 g) baking powder
Instructions
- Whisk the egg in a medium bowl until smooth.
- Add the chocolate chips, cocoa powder, sugar, oil and baking powder. Stir until the batter is thick, glossy and uniform, with no dry pockets.
- Lightly spray a 10‑oz. (or larger) microwave-safe mug or ramekin with non-stick spray. Pour the batter into the prepared vessel and tap gently to level.
- Microwave on high for 1 minute. The top should look set while the center remains slightly glossy—avoid overcooking.
- Let the cake rest about a minute, then serve warm.
Notes
- Remove the mug at exactly 1 minute even if the center looks a touch underdone; residual heat will finish it.
- Use a mug or ramekin that holds at least 10 oz to prevent overflow while the batter rises.
- Microwave power varies; ovens under 1000 watts may need 10–15 extra seconds. For very powerful microwaves, check a little sooner.
- Check ingredient labels for gluten or cross-contamination if you need the recipe to be gluten-free.
- This cake is best eaten immediately; its texture changes if stored.
Nutrition
Serving: 1 serving • Calories: 435 kcal • Carbs: 34 g • Protein: 10 g • Fat: 31 g
Nutrition information is an approximation.
How to Make Flourless Mug Cake Step-by-Step
Gather the ingredients: Measure everything and lightly coat a 10‑oz or larger microwave-safe mug or ramekin with non-stick spray so the cake releases easily when done.
Whisk the batter: Beat 1 large egg until smooth, then add 2 tbsp chocolate chips, 2 tbsp cocoa powder, 1 tbsp sugar, 1 tbsp oil and 1/4 tsp baking powder. Stir until the mixture is uniform, glossy and thick, scraping the bowl so no dry cocoa remains. Transfer the batter to the prepared mug and tap gently to level.
Microwave on high for 1 minute: Watch the cake as it cooks; the batter will rise significantly before settling. The surface should look set while the center may still shine slightly. Avoid cooking until completely matte, which leads to dryness.
Serve immediately: Let the cake cool for a minute so it’s comfortable to eat, then enjoy with a spoon while the center is still warm and fudgy.
Serving Suggestions
This cake is delicious on its own straight from the mug, but you can elevate it with a few simple additions:
- Scoop of vanilla ice cream: The contrast of cold ice cream and warm cake is classic and indulgent.
- Whipped cream and fresh berries: A dollop of whipped cream and a few raspberries or strawberries cut through the richness and add freshness.
- A cup of coffee: Serve with coffee for a cozy, low-effort dessert pairing.
Storage & Freezing Instructions
This mug cake is best eaten immediately. If you have leftovers, refrigerate them for up to 24 hours, but expect the texture to become denser and less tender.
Freezer
Freezing the finished cake is not recommended because the texture won’t recover well. Instead, prepare a dry mix of cocoa powder, sugar and baking powder in a small jar or bag to store for up to three months. When you want a cake, add the egg, oil and chocolate chips and proceed as directed.
Reheating
To reheat chilled cake, microwave for 10–15 seconds to soften the center. It won’t be identical to freshly cooked, but it will be warm and enjoyable.
More Flourless Recipes
- Flourless Brownies: A full-size version that uses the same basic idea for a larger batch.
- Flourless Chocolate Cake: A richer, party-sized flourless cake for special occasions.
- Flourless Banana Bread: A fruit-forward flourless loaf that puts ripe bananas to good use.
- Flourless Chocolate Cookies: Simple, portable cookies that satisfy a chocolate craving without flour.