S’mores Layer Cake with Homemade Fluff

This s’mores layer cake is made up of graham cracker flavored cake layers, frosted with chocolate Swiss meringue buttercream and homemade heavenly marshmallow fluff.

Two years ago when I first published this post, the photos were…let’s just not talk about it. This s’mores cake though, definitely worth updating. If I recall correctly, someone who tasted this cake said 

“Is this girl married? Cuz if not, then all she needs to do to get married is bake this cake!”

LOL…I am married, and not because of this cake. 

What makes this the best s’mores cake?

  1. It actually tastes like a giant s’mores!
  2. It’s sweet because (it’s s’mores) and because of the meringue but I balanced it with dark chocolate instead of traditional milk chocolate. If you prefer milk, that’s fine too but I don’t like how sweet a traditional s’more is.
  3. The cake is versatile – can be made with dairy-free and gluten-free options.

If you love a good s’mores treat, I also have marbled s’mores cupcakes, peanut butter s’mores cupcakes, the BEST s’mores donuts, s’mores cookies, s’mores cinnamon rolls, s’mores brownie ice cream, homemade s’mores frap,

What is a s’mores cake?

I went on a whole rant about this in my peanut butter s’mores cupcakes post but I’ll say it again. Why is it that when you search the internet for a s’mores cake/cupcake, everyone bakes a chocolate cake recipe?! Chocolate is so not the star flavor here, friends. Yes, it’s important, you can’t make a s’more without chocolate but it’s the smallest part of a s’more. 

This s’mores cake consists of graham cracker layers, chocolate Swiss meringue buttercream and marshmallow fluff. Aka 7-minute frosting, aka meringue frosting, whatever you want to call it. It’s pretty simple if you ask me and it tastes like an actual s’more in cake form!

How to make a s’mores layer cake?

Layer cakes can be intimidating but I promise, if you follow every instruction, you will succeed. Ok, I’m not going to make promises I can’t keep but most likely, you will succeed. It’s really not my fault if your oven temperature is not accurate or if you don’t grease your pans properly, etc. Just saying…

Ingredients

  • Flour: I always use all-purpose flour. Cake flour would also work well for this cake. I HIGHLY recommend measuring it with a digital scale though.
  • Graham Crackers: I just used one sleeve of crackers (like one packed wrapped together that has a bout 8-9 crackers). Pulse these until they’re as fine as they’ll get.
    • I don’t recommend store bought crumbs, they taste more stale.
  • Cinnamon: cinnamon is my secret weapon and totally optional but highly recommended.
  • Baking powder: well, it is a cake so obviously.
  • Salt: Salt brings out the flavor in all baked goods! I like fine sea salt.
  • Sugar: I just love a good combination of granulated sugar and brown sugar. They play different roles in flavor and texture of the cake but substitutions are allowed if necessary. 
  • Butter: Make sure it’s room temperature. Not cold, not softened and greasy, not melted. If you’re going to microwave your butter anyway, slice it and do it on 5 second intervals, rotating every time. Lol, I’m a pro if you can’t tell. 
  • Oil: I prefer to use half butter and half oil in my cakes because I like the texture better. Oil adds more moisture, while butter allows you to incorporate the air and gives good flavor and structure to the cake. Use a neutral flavor like canola, sunflower, or vegetable oil.
  • Eggs: I always use large eggs. I know you guys ignore that part of every recipe that says “use room temperature eggs” but I’m going to say it anyway. Use room temperature eggs. Place them in warm water for at least a few minutes before if they’re cold.
  • Buttermilk: You can use a homemade buttermilk substitute but just remember substitutes are always substitutes and not the real deal. 
    • I recently made this cake for my brothers wedding and tweaked it to make it more like my vanilla cake and I loved it! I did 3/4 cup of sour cream and 1/2 cup of milk.
  • Vanilla: I like to use vanilla extract in the cake and vanilla bean paste or real vanilla beans in the meringue.
  • Cocoa Powder: I use dutch-processed cocoa powder but any kind of unsweetened cocoa powder works fine for the frosting.
  • Dark Chocolate: I used dark chocolate because I think it balances the sweetness of the meringue better. You can certainly use milk chocolate or semi-sweet chocolate as well. 
  • Heavy Whipping Cream: Heavy cream is used to make chocolate ganache for the buttercream. I like 36-40% fat.

How to make your meringue stable

I have A. LOT. OF. EXPERIENCE. with meringue. In the past, when I was a beginner, I made meringue all the time with no issues. I’m telling you I made it on this cake and my gingerbread cake (these were in like 2018) without stabilizing it and it was fine. I froze those cakes and defrosted them without them ever weeping. 

Then I moved from my first house and I never made a meringue the same way again. I don’t know what happened but I’ve since been a part of the weeping meringue club. So what does Bernice do when things aren’t turning out perfectly? Study them. I study it all.

Here are my cliff notes on stabilizing meringue:

  1. Use a stand mixer with a metal bowl and the whisk attachment. Clean them all well and then wipe them down with vinegar. 
  2. Use room temperature egg whites, they’ll whip up much better.
  3. Use the Italian Method because cooking the sugar to a higher temperature definitely makes it more stable. 
  4. Add a little bit of honey (like just a teaspoon or so) to my sugar and water because it’s an inverted sugar which prevents the sugar syrup from crystallizing. The flavor is VERY subtle but if you’re sensitive to honey you may notice it (I don’t love honey in general but I love it in meringue). If you don’t want any flavor, you can use corn syrup or glucose syrup. 
  5. I normally add a tablespoon of lemon juice, a tsp of vinegar or 1/4 tsp of cream of tartar to meringue because the acidity also helps stabilize it.
  6. Whip just until you get stiff peaks, no more no less. 
  7. Add 1/8 tsp of gelatin per two egg whites. This is not traditional and it does alter the consistency slightly by “setting” it but 1/8 tsp is soooo little that it’s hardly noticeable and all it does it gelatinize the water that’s trying to “weep” out. 
  8. The last thing is toasting it. The meringue will hold it’s shape much better if it’s toasted but the inside of it may still soften over time. 

This is what I do when I want a meringue to stay put for an unlimited amount of time. If I do this, I can freeze and unfreeze a meringue several times without any weeping! 

You don’t HAVE to do all of these steps but I would say the main one that stabilizes the meringue is the gelatin. Just don’t add more than I did or you may get an actual marshmallow LOL. I only recommend doing this if you plan on freezing something or need it to hold up really well in a layer cake and you aren’t serving it right away. I did this for my brothers wedding cake (with this cake) and refrigerated it for two days and it was perfect.

Frequently Asked Questions

Can I make this s’mores cake dairy free?

You can use dairy free buttermilk in the cake and dairy free butter in the buttercream. For the ganache, you could just whatever dairy free heavy whipping cream replacement you prefer or a combination of dairy free butter and milk.

Can I make this s’mores cake gluten-free?

All my cake recipes that I tested did really well with gluten-free flour mixes like Bobs and King Arthur 1:1 so this one should work fine as well.

What other size pan can I make this

This recipe works well as a
– 3 or 4 six inch pans
– 2 eight or 9 inch pans
– 1 9×13 inch pan
– 22(ish) cupcakes

How to store layer cakes?

You can store the cake at room temperature for 1 day. If it’s any longer, I recommend storing it in the refrigerator for up to a week. If any slices have been cut out, cover the open side of the cake with plastic wrap and store slices in an airtight container. 

So glad you stopped by for a sassy little read today, I hope you guys enjoy this cake as much as we did. Make sure to tag me @baranbakery on instagram if you make it. If you have any questions at all, comment below or send me a message. As always, have a blessed day and happy baking!

Love, B

Yield: 6-inch cake, serves 8-10 slices

S'mores Layer Cake Recipe

s'mores cake with marshmallow fluff and chocolate frosting

This s’mores layer cake consists of graham cracker flavored cake layers, frosted with chocolate Swiss meringue buttercream and homemade heavenly marshmallow fluff.

Prep Time 1 hour
Cook Time 35 minutes
Additional Time 1 hour
Total Time 2 hours 35 minutes

Ingredients

Cake

  • 1/2 cup (about 1 sleeve or 8-9 sheets of graham crackers) graham cracker crumbs
  • 2 cups (240g) all-purpose flour, spooned and leveled
  • 1 Tbsp (10g) baking powder
  • 1/4 tsp salt
  • 1/4 tsp cinnamon *optional
  • 1/4 cup (56g) unsalted butter, room temperature
  • 1/2 cup (118mL) canola oil
  • 1/2 cup (100g) granulated sugar
  • 1 cup (190g) light brown sugar, lightly packed
  • 1/2 Tbsp vanilla extract
  • 3 large eggs, room temperature
  • 1 cup (237mL) buttermilk

Meringue Frosting/Marshmallow Frosting

  • 6 (200g) large egg whites, room temperature
  • 1 1/2 cups (300g) granulated sugar
  • 1/2 Tbsp vanilla bean paste

Chocolate Swiss Meringue Buttercream

  • 4 oz dark chocolate chips
  • 1/2 cup (118mL) heavy cream
  • 1/2 of Meringue frosting
  • 1 cup (227g) unsalted butter, room temperature
  • 1/2 cup (40g) Dutch-process cocoa powder, spooned and leveled
  • pinch of salt

Instructions

Graham Cracker Cake

  1. Preheat the oven to 350F/177C convection (or 325F/162C conventional) and grease and line three 6-inch (15.24 cm) cake pans with cooking spray and parchment paper. 
  2. Place 1 sleeve of graham crackers in a food processor and turn it on high until there are no more large chunks. In a medium bowl, whisk together the flour, graham cracker crumbs, baking powder, salt, and cinnamon. Set the dry ingredients aside. 
  3. In an electric mixer fitted with the whisk attachment, beat the butter, oil, granulated sugar, brown sugar and vanilla extract together, on medium speed, until they’re light and fluffy. This should take 2 to 3 minutes.
  4. Add the eggs, one at time, beating well after each addition. Make sure to scrape the bottom of the bowl as needed.
  5. In five increments, alternate adding the dry ingredients and buttermilk into the batter, beginning and ending with the dry ingredients. Beat the mixture on medium speed, just until the flour is fully incorporated, making sure to scrape the edge of the bowl as needed.
  6. Distribute the batter evenly among the prepared pans and bake for 30-35 minutes, until the cake springs back when it’s poked. Remove the cakes from the pans and allow them to cool completely before frosting.

Meringue Frosting/Marshmallow Frosting

  1. Begin by thoroughly cleaning the aluminum bowl and the whisk attachment of the stand mixer (they can’t have any fat residue when making meringue). Once they’re clean and dry, place the egg whites and the granulated sugar in the bowl.
  2. In a small saucepan, bring 1/2 cup (118mL) of water to a simmer. Keep the water simmering on low heat and place the bowl with the egg whites and sugar on top of the saucepan, creating a double boiler. Whisk the egg whites and sugar over low heat for 5 to 10 minutes, until the sugar granules are dissolved. You can feel it between your fingers if the sugar is fully dissolved or you can use a candy thermometer and bring the mixture to about 150°F (65°C).
  3. When the sugar granules are fully dissolved in the egg whites, remove the bowl from the heat and place it on the stand mixer fitted with the whisk attachment. Beat the mixture on medium-high speed, until stiff peaks form.
  4. Add the vanilla and continue beating the mixture until it's no longer warm. This usually takes about 10-15 minutes. Remove half of the meringue into a separate bowl and set aside.

Chocolate Swiss Meringue Buttercream

  1. Place the dark chocolate in a medium bowl and in a small saucepan, heat the heavy cream until it's simmering. Pour the heavy cream over the chocolate and let it melt for 1-2 minutes. Stir until the chocolate is completely smooth. Set it aside to cool completely.
  2. Place half of the meringue back on the stand mixer and lower the speed to medium. Slowly add in the softened butter, 2 to 3 tablespoons at a time. Once the butter is all incorporated, continue beating on medium speed for a few minutes until it emulsifies into a buttercream (it may go through phases of looking soupy and/or curdled before it emulsifies but it should come together within 5-10 minutes). 
  3. Once the buttercream comes together, add in the cocoa powder, salt and only HALF of the melted chocolate.

Assemble the Cake

  1. Place the first layer of cake on a cake board and spread a thin layer of chocolate buttercream on top. Then spread a layer of meringue frosting and a swirl of chocolate ganache (you can reheat the chocolate in the microwave for 5-10 seconds if necessary). Repeat with the second layer and then place the third layer of cake on top.
  2. Smooth out any buttercream that squished out between the layers and refrigerate for at least 60 minutes. Place the rest of the chocolate buttercream on top of the cake and use an offset spatula to work it’s way down the sides. Add in dabs of meringue frosting and chocolate ganache, lightly spreading them in. Top with extra graham cracker crumbs, or even toasted marshmallows if you’re not lazy!

Notes

  • If the chocolate Swiss meringue buttercream or the meringue frosting is too soft, refrigerate them for 20 minutes before frosting the cake. It's better for them to be slightly too firm instead of too soft.

Nutrition Information:

Yield:

10

Serving Size:

1

Amount Per Serving: Calories: 858Total Fat: 45gSaturated Fat: 21gTrans Fat: 0gUnsaturated Fat: 22gCholesterol: 132mgSodium: 361mgCarbohydrates: 105gFiber: 2gSugar: 79gProtein: 10g

Nutrition information isn’t always accurate.

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    • If you make a solid border with the buttercream you could but I found that marshmallow fluff seeps out a lot easier so I don’t like using it. I recommend refrigerating the buttercream for a few minutes so it’s little more firm and then even refrigerating the cake between stacking layers.

  1. I made this. I turned temp to 335 and cooked 5 minutes longer. I find that helps the center cook without burning the edges. The cake was perfect. I actuallybused a hershey milk chocolate custard for the filling but used the swiss meringue buttercream on the outside it was a hit! Thank you

  2. Yes! I agree! Why is chocolate always the base for smores. Can’t wait to try this cake. I’m working on some smores recipes with graham cracker as the base flavor too!

  3. Would love to try this.

    Have you tried making this with two 9 inch pans? How long do you think the bake time should be adjusted to?

    • if it just stays runny then there was probably some fat somewhere that wouldn’t let it aerate. If you try it again, try wiping down the bowl and the whisk with a little vinegar before starting 🙂

  4. Hi! I made this cake for a birthday and it was delicious! Incredibly easy to make but looks like you spent hours. Only weird thing is that the next day the cake tasted sour? I ended up tossing it sadly. I kept it in the fridge and none of my ingredients had gone bad or near their expiration date. the cake was in the fridge and not near any other food items. Just confused on what happened.

    • Hi Diana, I’m glad the cake turned out well at first. I believe that happened to me once as well with meringue on a different cake and I think maybe the egg white in the meringue went bad. I’ve made hundreds of meringues and it only happened to me once so Idk if it was just a faulty egg? I’m sorry you had to throw it out 🥴

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