Easy S’mores Sheet Cake

This s’mores sheet cake is made with a simple graham cracker cake base and frosted with chocolate ganache (basically melty chocolate) and the best homemade vanilla toasted marshmallow fluff! 

I don’t know if you knew this but S’mores is one of my all time favorite flavor combinations even though I don’t really care for a traditional s’mores treat. They’re too sweet, too gooey and just could be better. The flavor combination though, is superior. That’s why I have a million s’mores recipes lol. 

This sheet cake is a riff on my very popular S’mores Layer Cake – one of the first recipes I’ve ever made and still a favorite. I think you’ll also love my GORGEOUS Chocolate S’mores Cake

How To Make S’mores Sheet Cake, Step-By-Step Photos

Graham Cracker Cake

  1. Cream the butter with the sugar and the oill.
  2. Beat in the eggs, one at a time. 
  3. Alternate adding the dry and wet ingredients, in 3-4 increments. 
  4. Bake in a 9×13” or 10” square pan. 
  5. Once it’s cooled, poke holes about ½-Âľ of the way down, using a straw. 

Chocolate Ganache

  1. Melt the chocolate with the heavy cream, let it cool and thicken slightly.
  2. Spread on top of the cake. 

Marshmallow Fluff

  1. Whisk sugar, cream of tartar and egg whites over a double boiler. 
  2. Sugar has to be fully dissolved in the egg whites before whipping & reaches 170F (77C). 
  3. Egg whites and sugar fully whipped into a fluffy meringue, about 10 minutes. 
  4. Use meringue to frost the top of the cake and toast it using a culinary torch

Storing & Serving Cake

The cake can be served fresh right away or if it’s served within a couple hours, it can stay out.

Because of the meringue topping, the cake does need to be stored in the refrigerator if it’s been several hours or overnight. Make sure it’s airtight so it doesn’t dry out. Serve within a week for the best flavor and texture.

The cake can also be frozen for weeks/months as long as it’s stored airtight! 

That’s all today, I hope you love this s’mores cake as much as I do! 

If you have any questions, please comment down below – those will get answered much quicker than email or through social media. 

If you’ve tried this, I would very much appreciate a star rating or review as well.

As always, have a blessed day and happy baking!

Love, B

meringue on top of a graham cracker cake

Easy S’mores Sheet Cake

Bernice Baran
This s’mores sheet cake has a graham cracker flavored cake layer, a milk chocolate ganache that drips into the cake a little and the best fluffiest homemade marshmallow fluff.
No ratings yet
Prep Time 1 hour
Cook Time 35 minutes
Additional Time 1 hour
Total Time 2 hours 35 minutes
Course Cakes
Cuisine American
Servings 24 slices
Calories 279 kcal

Equipment

Ingredients
  

Cake

  • 65 grams (1/2 cup) graham cracker crumbs about 1/2 sleeve or 4-5 sheets of graham crackers
  • 240 grams (2 cups) all-purpose flour spooned and leveled
  • 10 grams (1 Tbsp) baking powder
  • 1/2 tsp fine sea salt
  • 1/4 tsp cinnamon *optional
  • 56 grams (1/4 cup) unsalted butter room temperature
  • 120 mL (1/2 cup) canola oil
  • 100 grams (1/2 cup) granulated sugar
  • 200 grams (1 cup) light brown sugar lightly packed
  • 1 Tbsp vanilla extract
  • 3 large eggs room temperature
  • 240 mL (1 cup) buttermilk*

Chocolate Swiss Meringue Buttercream

  • 340 grams (2 cups/12 oz) milk chocolate chips**
  • 120 mL (1/2 cup) heavy cream

Meringue Frosting/Marshmallow Frosting***

  • 4 large egg whites (120g) room temperature
  • 200 grams (1 cup) granulated sugar
  • 1/4 tsp cream tartar
  • 1 Tbsp vanilla bean paste
  • tiny pinch sea salt

Instructions
 

Graham Cracker Cake

  • Preheat the oven to 350F/177C convection (or 325F/162C conventional) and grease and a 9×13" cake pans with cooking spray and parchment paper. 
  • Place the 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. 
    65 grams (1/2 cup) graham cracker crumbs, 240 grams (2 cups) all-purpose flour, 10 grams (1 Tbsp) baking powder, 1/2 tsp fine sea salt, 1/4 tsp cinnamon
  • In an electric mixer fitted with the whisk attachment, beat the butter, oil, granulated sugar, light brown sugar and vanilla extract together, on medium speed, until they’re light and fluffy. This should take 2 to 3 minutes.
    56 grams (1/4 cup) unsalted butter, 120 mL (1/2 cup) canola oil, 100 grams (1/2 cup) granulated sugar, 200 grams (1 cup) light brown sugar, 1 Tbsp vanilla extract
  • Add the eggs, one at time, beating well after each addition. Make sure to scrape the bottom of the bowl as needed.
    3 large eggs
  • 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.
    240 mL (1 cup) buttermilk*
  • Spread the batter evenly in the prepared pan and bake for about 30-35 minutes, until the cake springs back when it’s poked. Remove the cake from the oven and allow it to cool completely before frosting.

Milk Chocolate Ganache

  • Place the milk 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.
    340 grams (2 cups/12 oz) milk chocolate chips**, 120 mL (1/2 cup) heavy cream
  • Allow the chocolate ganache to cool for just a few minutes so it's no longer hot.
  • Meanwhile, use a straw to poke holes into the cake going down only about 1/2-3/4 of the way. Spread the chocolate ganache on top of the cake. Refrigerate it while you make the meringue.

Meringue Frosting/Marshmallow Frosting

  • 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.
    4 large egg whites (120g), 200 grams (1 cup) granulated sugar, 1/4 tsp cream tartar
  • 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, sugar and cream of tartar on top of the saucepan, creating a double boiler. Whisk the egg whites and sugar over low heat for about 10 minutes, until the sugar granules are completely 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 175°F (80°C).
  • When the egg whites reach temperature, 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, about 10 minutes.
  • Add the vanilla and salt and continue beating the mixture until it's well combined. Spread the meringue on top of the set chocolate layer and use a kitchen torch to toast the top.
    1 Tbsp vanilla bean paste, tiny pinch sea salt

Notes

*You can use a homemade buttermilk by mixing 1 cup of milk with 1 Tbsp of lemon juice or vinegar. 
**S’mores generally uses milk chocolate so I made this more nostalgic but if you’re like me and you like an elevated, less sweet s’mores treat, use dark chocolate instead of milk. I recommend adding an extra 1-2 Tbsp of heavy cream if using dark chocolate. 
***If you’re worried about the meringue weeping, make sure to get a thermometer and take the eggs to 175C – I promise it makes all the difference and don’t skip the cream of tartar. 
Alternatively if you need the meringue to last a long time, you may add in 1/4 tsp gelatin. Dissolve it in 1-2 tsp of cold water, let it set and then microwave it for 5 seconds before adding it into the fully whipped cream. Mix just until it’s well combined. Then when you refrigerate it, the meringue will set a bit and last a long time without weeping – can even be frozen like this. 

Nutrition

Serving: 1gCalories: 279kcalCarbohydrates: 37gProtein: 3gFat: 14gSaturated Fat: 6gPolyunsaturated Fat: 2gMonounsaturated Fat: 4gTrans Fat: 0.1gCholesterol: 32mgSodium: 142mgPotassium: 108mgFiber: 0.4gSugar: 26gVitamin A: 179IUVitamin C: 0.03mgCalcium: 65mgIron: 1mg
Tried this recipe?Let us know how it was!
Share your love

Leave a Reply

Your email address will not be published. Required fields are marked *

Recipe Rating