S’Mores Mug Cake: Your Favorite Campfire Dessert in a Mug

If you’re craving all the gooey, chocolatey goodness of a campfire s’more but don’t have a fire pit handy, this S’mores Mug Cake is about to be your new favorite dessert hack. Made with graham cracker crumbs, melted chocolate, and marshmallows, this single-serve cake has all the nostalgic flavors of the classic treat — without the mess or the wait. The best part? It comes together in just a few minutes in the microwave, making it a quick and easy dessert for late-night cravings, after-school snacks, or whenever you want a cozy sweet treat.

This post may contain affiliate links. Please read my disclosure for more info. 

S’mores in a Mug

Gooey marshmallow, crunchy graham crackers, and sweet melted chocolate…😍

I LOVE s’mores!

It’s one of those well-rounded desserts that hits the important dessert food groups.

But camping season is short here. There are really only a couple of months to make s’mores on the campfire.

So I took all those yummy smores flavors, and mixed them in a mug, microwaved, and made this quick and easy s’mores mug cake version..

If you love marshmallows and chocolate, make sure you check out this hot chocolate bomb mug cake. 😋

S’Mores Mug Cake Ingredients

Here are the yummy ingredients you will need to make your favorite campfire treat in a mug:

(sampling strongly encouraged while making it…)

• flour
• graham cracker crumbs
• sugar, and kind that is granulated
• unsweetened cocoa powder
• baking powder
• salt
• milk, any kind
• vegetable oil (or melted butter)
• vanilla extract (pure is best)
• chocolate chips or chopped chocolate
• mini marshmallows

For more delicious chocolate mug cakes, check out this chocolate mug cake roundup.

Microwave S’mores: Tips and Tricks

Use a bigger mug: Pick a 10–12 oz microwave-safe mug so your cake has room to rise without spilling over.

Catch any spills: Put your mug on a plate or paper towel to catch if any spills do happen the first time you make this s’mores mug cake and are figuring out timing.

Don’t overcook it: Mug cakes can go from gooey to dry fast. Start with 1 minute in the microwave and add 10-second bursts if needed.

Add extra chocolate: Tuck a square of chocolate or a spoonful of Nutella into the center of the batter before microwaving for a molten lava effect.

Make it gluten-free: Substitute gluten-free graham crackers or gluten-free flour for a just-as-delicious alternative.

How to Get That S’mores Toasted Marshmallow Look

There are two main ways to toast your marshmallows in the kitchen.

The first one is to use the broiler:

After cooking this smores mug cake, add more marshmallows to the top and put the (oven-safe) mug under your pre-heated broiler.

Do not step away from the marshmallows! Broilers broil very quickly, so toasting marshmallows this way will only take 20 seconds to about 1 minute or so.

I don’t love this method, because I find it goes from not toasty to burnt too quickly. But hey, this is how roasting marshmallows can go on the campfire, so maybe this method feels more authentic.

The toasted marshmallow method I prefer is using a kitchen torch:

This inexpensive and fun little gadget means no turning on an oven, and I find it easier to get the marshmallows nice and toasty without getting to the burnt stage.

‘K, let’s make this s’more. These s’mores? Call it what you want, let’s make it.

S'mores Mug Cake

Yield: 1 serving

Prep Time: 2 minutes

Cook Time: 2 minutes

Craving s’mores without the campfire? This gooey, chocolatey S’mores Mug Cake is packed with graham cracker crumbs, melted chocolate, and marshmallows — ready in just minutes for the perfect quick dessert.

Print

Ingredients

• 3 tablespoons all-purpose flour
• 2 tablespoons graham cracker crumbs (about 1 graham cracker)
• 2 tablespoons sugar
• 1 tablespoon unsweetened cocoa powder
• 1/4 teaspoon baking powder
• Pinch of sea salt
• 3 tablespoons milk (any kind)
• 1 tablespoon vegetable oil (or melted butter)
• 1/4 teaspoon pure vanilla extract
• 2 tablespoons chocolate chips or chopped chocolate
• 2 tablespoons mini marshmallows

Instructions

1. Mix the flour,graham cracker crumbs, sugar, cocoa powder, baking powder, and salt in a microwave-safe mug (at least 10–12 oz).
2. Stir in the milk, oil (or melted butter), and vanilla until smooth.
3. Stir in the chocolate chips and mini marshmallows.
4. Microwave on high for 1 minute to 1 minute 30 seconds, or until the s'mores mug cake is set but still moist.
5. Top with more marshmallows and microwave for another 5–10 seconds, just until melty — or use a kitchen torch to toast them for that classic s’mores look.
6. Grab a spoon and enjoy straight from the mug!