These easy S'mores Blondies are the ultimate ode to the best campfire treat! Made with a gooey graham cracker blondie, filled with dark chocolate chips and topped off with toasted marshmallows.
Tell me about these blondie bars
- Super gooey soft graham cracker cinnamon blondie. These s'mores blondie brownies are made with graham crackers packed straight into the batter. This makes the blondies particularly soft and flavourful. A touch of cinnamon also helps to add the cozy campfire vibe.
- Loaded with dark chocolate chips. Nothing goes better in a s'more than a deep and rich dark chocolate to compliment the graham cracker and marshmallow. My blondies have a generous dose of dark chocolate chips, giving pockets of melt in your mouth chocolatey goodness in every bite!
- Toasted marshmallow topping. You can't really have a s'more without toasted marshmallow! This topping couldn't be any easier - just pile on some mini marshmallows, broil and enjoy!
- Great to make ahead. These blondies stay good for days and are sure to be a favorite for barbecues, picnics or a sweet snack anytime! They travel well in a single layer, so are a great option for cook outs or camping.
To make these s'mores inspired beauties, you'll need:
- Butter - unsalted butter, melted. You can substitute with salted butter here, but it will add extra salt to the overall recipe. If using salted butter, I'd recommend reducing the added salt by about half.
- Light brown sugar - firmly packed. This will give a cozy richness to the blondie.
- Sugar - granulated sugar or caster sugar.
- Eggs - large eggs, ideally at room temperature for baking. Room temperature eggs will mix better into your batter.
- Vanilla extract
- Flour - all purpose flour or plain flour work in this recipe.
- Cornstarch - this will help lighten the blondies, giving them a softer texture. In the UK cornstarch is referred to as cornflour (but in the US cornflour is a completely separate ingredient that should not be substituted here).
- Baking powder
- Ground cinnamon
- Graham cracker crumbs - you can use store bought crumbs or blitz some whole graham crackers in a food processor until you have a fine crumb. This recipe uses the crumbs from about 5 crackers.
- Chocolate chips - dark chocolate chips are my favorite in this recipe for giving the classic flavour of s'mores. You could use any chocolate chip (milk chocolate, semi-sweet, etc.) or solid chocolate cut into chunks.
- Mini marshmallows - you'll want a good amount of mini marshmallows to coat the top of your blondies. If you don't have mini ones, you can use regular sized, but these won't normally give as good of coverage. Read the notes about marshmallows below for some tips and options.
How to Make S'mores Blondies
This recipe is designed for an 8" square baking tray and is achievable with one bowl. The process is pretty straightforward:
- Start off by preheating the oven and lining your baking pan.
- In a mixing bowl, whisk together the melted butter with the sugars, until the sugar is emulsified and the mixture a bit lightened. I usually mix for about 2 minutes.
- Add the eggs and the vanilla, beating to combine (image 1 below).
- Next sift the flour, cornstarch, baking powder, cinnamon and salt into the bowl. Add the graham cracker crumbs too. Stir everything together with a spatula until you have a thick batter (image 2 below). Try to avoid overmixing, but also ensure that you've not left any pockets of flour!
- Add the chocolate chips and stir to combine.
- Pour this into your baking dish and spread evenly into the sides and edges (image 3 below).
- Bake in a preheated oven until a toothpick inserted about 2 inches in from a corner comes out mostly clean.
- Remove and cover with mini marshmallows (images 4 and 5 below).
- Then, changing your oven settings to broil, return the pan to the oven. Broil until the marshmallows begin to swell up and go golden (or as toasted as you normally like your s'mores marshmallows to be!).
- Remove from the oven and allow to cool for about an hour before slicing (image 6 below).
Notes on Marshmallows for this Recipe
Marshmallows are essential to s'mores! There are a few easy ways to achieve the marshmallow topping here and some key tips to remember when making your choices.
1. Mini marshmallows
This recipe calls for mini marshmallows. This is because they are, in my opinion, the easiest (and best) way to get the results I wanted - a full coverage of toasted marshmallow globules on top of my s'mores blondies.
- Benefits: quick and easy full coverage, no need for extra utensils. Just sprinkle over the top and toast.
- Downsides: mini marshmallows aren't always readily available.
2. Full size marshmallows
Another option for topping your blondies is to use full size marshmallows.
- Benefits: generally more available than mini marshmallows.
- Downsides: for best coverage, you'll need to cut the full size marshmallows up, at least in half. Otherwise, you can cover the blondies in the full size ones, but this will be a very thick marshmallow coating, which I feel overwhelms the blondie. (They're also more messy to cut!)
3. Marshmallow fluff
I'm a huge fluff fan! If I had to pick a backup option to mini marshmallows, I'd probably go for fluff.
- Benefits: spreadable over your blondies and always fun.
- Downsides: a bit messy and prone to running. Also, I find fluff a little difficult to toast under the broiler as it catches quickly.
4. Marshmallow buttercream
An option that doesn't involve too much super sticky marshmallow is my easy marshmallow buttercream.
- Benefits: not as sticky as the other options here. Spreadable and pipeable, plus easier to store and freeze than traditional marshmallows, because it is less sticky.
- Downsides: does involve dealing with a separate process, mixing up the buttercream. Also, sadly, it can't be toasted! Trying to put my marshmallow frosting under the broiler will result in a runny mess - so please don't try it at home!
Some of my quick top tips for ensuring success with these s'mores blondies:
- Line your baking pan! I know it takes a little extra effort, but it makes it a lot easier to serve the blondies. If you line with a criss cross of parchment paper, you'll be able to lift them straight out when ready to serve.
- Don't sift the graham cracker crumbs. While you'll be sifting your other dry ingredients, don't add the cracker crumbs to the sieve. Dependent on the size of your sifter, you'll find the crumbs just get stuck and there's no need or benefit to trying to sift them.
- Baking until a toothpick comes out mostly clean instead of completely clean is the trick to a gooey blondie. If you bake it until a toothpick inserted in the centre is completely clean, it will be a drier bake.
- Keep an eye while broiling the topping - marshmallows brown quickly once they get started. You don't want them to roast completely or catch on fire!
- If you have a kitchen torch available, you can use this to toast the marshmallows instead of the broiler function on the oven.
- Let the blondies cool for an hour before attempting to slice. Gooey blondies or brownies need to cool down to firm up enough to easily handle. You can certainly cut into them sooner, but it will be messier!
- Using a well oiled knife will make slicing through the marshmallow less messy!
Some Easy Variations
- Different types chocolate - dark chocolate works really well with this recipe, providing a strong enough flavour without excessive sweetness to compliment and work with the rest of the s'mores ingredients. You can, however, most definitely make this recipe with other chocolate. Milk chocolate, semi-sweet chocolate or white chocolate would all work well in this recipe, dependent on your preferences.
- Chocolate chunks or chopped chocolate - just like the type of chocolate you use, the size of the pieces is really up to personal preference. I find chips easy and convenient, but this recipe will also work with chunks or chopped solid chocolate bars. If your pieces of chocolate are particularly big, you may find it difficult to spread the batter.
- Cookie crumbs - I'm a traditionalist with these graham cracker blondies. But, you could substitute the graham cracker crumbs for other cookie crumbs if you don't have these available or want to try something different. Lotus Biscoff cookies work well here, giving an extra caramlised flavour. Alternatively, any fairly dry brittle cookie, that can be crumbed easily in a food processor, should work well!
- Extra toppings - you could add some extra cookie pieces, chocolate chips or sprinkles to decorate the top of these. The toasted marshmallows won't be super sticky on the surface, after browning in the oven, so any extra toppings are best something that can be pressed into place, like larger chunks of graham crackers.
My easy s'mores blondies with mini marshmallows will keep well for several days at room temperature. Ideally, store in an air tight container to preserve freshness. Wrapping with plastic wrap may stick to the marshmallow topping, so I'd avoid covering them tightly on top.
These graham cracker chocolate chip blondies with marshmallows will freeze fairly well. Allow them to cool completely at room temperature first, before storing in a freezer safe container for up to three months.
It is best to slice them first, to make for an easier access to individual brownies once defrosted. Avoid stacking them as they're prone to sticking together.
Defrost at room temperature before serving.
No, you have options! This recipe calls for mini marshmallows as I find these the easiest to work with to produce the results I wanted. But, you can absolutely use other options such as full size marshmallows, marshmallow fluff or even marshmallow buttercream.
For more details about the pros and cons to each of these toppings, see the section about Marshmallows for this Recipe above.
Looking for more gooey goodies? Try:
- 8" square baking tray
- 10 tablespoon unsalted butter melted
- 1 cup light brown sugar firmly packed
- ⅓ cup granulated sugar or caster sugar
- 2 large eggs at room temperature
- 1 teaspoon vanilla extract
- 1 cup all purpose flour or plain flour
- 2 teaspoon cornstarch
- ¼ teaspoon baking powder
- ½ teaspoon salt
- ½ teaspoon ground cinnamon
- ¾ cup graham cracker crumbs
- 6 oz dark chocolate chips
- 5 oz mini marshmallows
- Begin by preheating your oven to 350℉ (175C/155C Fan) and lining an 8" square baking pan with parchment paper.
- In a mixing bowl, whisk together melted butter and your sugars until well combined (about 2 minutes).
- Add the eggs and vanilla extract and again whisk to combine.
- Sift the flour, baking powder, cornstarch, salt and cinnamon into the mixing bowl. Then, add the graham cracker crumbs. Use a spatula to stir the batter together. It should be fairly thick and may have some small lumps due to the graham cracker crumbs. Avoid overmixing, but ensure there aren't any pocked of unmixed flour or dry ingredients.
- Add the chocolate chips to the batter and stir through.
- Pour the mixture into the prepared baking pan and spread in an even layer.
- Bake in the centre of the preheated oven for about 40 minutes, until a toothpick inserted about 2" from the corner of the pan comes out mostly clean.
- Remove from the oven and top with mini marshmallows.
- Change your oven to a broiler setting and cook under the broiler watching carefully until your marshmallows expand and toast to your taste. (see note)
- Allow your blondies to cool for about an hour to allow them to firm up enough for easy slicing. For best results, cut with an oiled knife. This will help limit the marshmallows sticking to the blade.
- This can be achieved with the broiler (in the UK referred to as grill). Set this to a medium setting and place your pan underneath, keeping an eye on the marshmallows. These will begin to puff up and go golden. They will burn quickly if unwatched, so do stay with them while you're toasting.
- As an alternative, you can use a kitchen blow torch to toast these marshmallows. Again this should be done carefully as marshmallows catch fast! Toast to your heart's content.
- The benefit of a kitchen torch is a bit more control of the areas being toasted, but it does require an extra piece of equipment, which not everyone will have available.