Irresistible S’mores Mug Cake

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Sometimes you’re craving s’mores but don’t want to light a campfire or turn on the oven. I get it. When that chocolate and marshmallow craving hits, you want it satisfied fast. That’s exactly when this s’mores mug cake saves the day.

This little treat takes just five minutes from start to finish. You probably have everything you need in your pantry right now – flour, cocoa powder, marshmallows, and graham crackers. Mix it up in a mug, pop it in the microwave, and you’ve got warm, gooey s’mores goodness without any fuss.

The best part? No dishes to clean except for one mug and a spoon. My kids love making these on rainy afternoons when they’re bored. It’s become our go-to treat when we want something sweet but don’t want to commit to a whole batch of anything.

What Kind of Cocoa Powder Should I Use?

For this s’mores mug cake, you can use either natural cocoa powder or Dutch-processed cocoa powder – both will give you that rich chocolate flavor you’re looking for. Natural cocoa powder tends to be a bit more acidic and will give you a slightly tangier chocolate taste, while Dutch-processed is milder and smoother. If you only have one type in your pantry, don’t worry about it – either will work perfectly fine for this quick mug cake. Just make sure your cocoa powder is fresh and hasn’t been sitting in your cabinet for years, as old cocoa can taste flat and won’t give you that deep chocolate flavor that makes this dessert so good.

Options for Substitutions

This quick mug cake is pretty forgiving when it comes to swaps:

• All purpose flour: You can use whole wheat flour or even oat flour if that’s what you have on hand. The texture might be slightly different, but it’ll still taste great.
• Brown sugar: White sugar works just fine here, or you can try coconut sugar for a slightly different flavor. You might need to add a tiny bit more liquid if using coconut sugar since it’s drier.
• Flavorless oil: Melted butter is a great substitute – just use the same amount. You can also try applesauce for a lighter version, though the cake will be a bit more dense.
• Cookie crumbs: Graham cracker crumbs are traditional for s’mores, but crushed digestive biscuits, vanilla wafers, or even crushed cereal like Golden Grahams work well too.
• Marshmallows: Mini marshmallows work better than large ones for even melting. If you only have large marshmallows, just cut them into smaller pieces before adding to the mug.
• Water: Milk adds extra richness to the cake, so feel free to swap the water for regular milk or even almond milk if you prefer.

Watch Out for These Mistakes While Cooking

The biggest mistake with mug cakes is overcooking them in the microwave, which turns your fluffy treat into a rubbery disaster – start with 60-90 seconds and check every 15 seconds after that since microwave power varies so much.

Another common error is not mixing the batter thoroughly, leaving you with pockets of dry flour or cocoa powder that create an uneven texture, so make sure to stir until completely smooth before microwaving.

Don’t add the marshmallows at the beginning or they’ll completely melt away – instead, press them gently into the top of the batter about halfway through cooking for that perfect gooey s’mores effect.

Finally, let your mug cake cool for at least a minute before digging in, as the center will be extremely hot and needs time to set properly for the best texture.

What to Serve With S’mores Mug Cake?

This s’mores mug cake is pretty much a complete dessert on its own, but a scoop of vanilla ice cream on top takes it to the next level – especially when it starts melting into all those gooey marshmallow bits! A cold glass of milk is always a great choice too, since it balances out the rich chocolate and sweet marshmallow flavors perfectly. If you want to get fancy, try serving it with some fresh strawberries or raspberries on the side for a little tartness that cuts through all that chocolatey goodness. You could even drizzle a bit of caramel sauce over the top if you’re feeling extra indulgent!

Storage Instructions

Best Fresh: This s’mores mug cake is definitely best enjoyed right away while it’s still warm and gooey. The marshmallows will be perfectly melted and the texture will be at its peak. If you do have leftovers, you can cover the mug with plastic wrap and keep it in the fridge for up to 2 days.

Make Ahead: You can actually prep the dry ingredients ahead of time! Just mix the flour, brown sugar, cocoa powder, and salt in your mug and store it covered at room temperature. When you’re ready for dessert, simply add the wet ingredients and toppings, then microwave as usual.

Warm Up: If your mug cake has cooled down or been in the fridge, just pop it back in the microwave for 15-20 seconds to get that warm, melty texture back. The marshmallows will soften up again and it’ll taste almost as good as fresh!

Preparation Time	5-10 minutes
Cooking Time	1-2 minutes
Total Time	6-12 minutes
Level of Difficulty	Easy

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 350-400
• Protein: 4-6 g
• Fat: 15-20 g
• Carbohydrates: 55-60 g

Ingredients

• 3 tbsp all-purpose flour
• 3 tbsp unsweetened cocoa powder
• 3 tbsp light brown sugar
• 3 tbsp neutral oil (such as canola, coconut, or sunflower)
• 3 tbsp water
• Pinch salt
• 1/2 tsp pure vanilla extract
• 2 tbsp crushed cookies
• 3 large marshmallows

Step 1: Mix the Mug Cake Batter

• 3 tbsp all-purpose flour
• 3 tbsp unsweetened cocoa powder
• 3 tbsp light brown sugar
• 3 tbsp neutral oil (such as canola, coconut, or sunflower)
• 3 tbsp water
• pinch salt
• 1/2 tsp pure vanilla extract

In a microwave-safe mug, combine the all-purpose flour, unsweetened cocoa powder, light brown sugar, neutral oil, water, salt, and pure vanilla extract.

Stir thoroughly until the mixture forms a smooth batter with no lumps.

Step 2: Microwave the Cake

• batter from Step 1

Microwave the mug with the batter for 45-60 seconds, or until the cake looks set and firm to the touch.

Timing may vary depending on your microwave’s wattage.

I recommend checking at the 45-second mark to avoid overcooking.

Step 3: Add Cookie Topping and Marshmallows

• 2 tbsp crushed cookies
• 3 large marshmallows

Once the mug cake is cooked, sprinkle the crushed cookies over the top.

Place the marshmallows on top of the cake and cookie layer.

Step 4: Microwave to Melt Marshmallows

• cake with cookie and marshmallow topping from Step 3

Microwave the mug cake topped with cookies and marshmallows for an additional 20 seconds, or until the marshmallows are soft and begin to puff up.

For extra gooey marshmallows, I like to let them sit for another 30 seconds in the mug before serving.

Step 5: Serve and Enjoy

Serve the mug cake warm, optionally topped with a scoop of vanilla ice cream for an extra treat.

Enjoy while the marshmallows are still gooey and the cake is soft.