S'mores Layer Cake

June  3, 2016
2 Ratings
Photo by Erin McDowell
  • Prep time 2 hours
  • Cook time 2 hours
  • Makes one BIG ol' 8-inch layer cake
Author Notes

This is a big, tall layer cake—worthy of any summer soirée you can dream up. You start with three layers of graham cake, which is slightly concave in the center. The concave cake cavity is perfect for a layer of ganache, making a flat surface for a layer of marshmallow that sandwiches it all together. Toasting the marshmallow is optional, but much more fun! —Erin Jeanne McDowell

What You'll Need
  • 1 GANACHE:
  • 4 cups chopped milk chocolate
  • 1 1/2 cups heavy cream
  • 3 x Graham Cake (
  • 2/3 cup cool water, divided (5.35 oz)
  • 2 envelopes granulated gelatin (5 teaspoons)
  • 2 cups granulated sugar (14.00 oz)
  • 1 tablespoon vanilla extract (15 g)
  1. Make the ganache: Place the chocolate in a large, heat-safe bowl. In a medium pot, bring the cream to a simmer over medium heat.
  2. Pour the hot cream over the chocolate and let sit, undisturbed, for 15 to 20 seconds. Using a silicone spatula, begin stirring in tight circles in the center of the bowl, eventually working in larger circles outward until the ganache is smooth and glossy. Set aside to cool to a spreadable consistency (20 to 30 minutes)—you can use the fridge or freezer to speed up the process, just keep an eye on it; you don't want it to be liquid anymore or look oozy, but you also don't want it to be hard or difficult to work with. Ideally, it should be spreadable, like thick frosting!
  3. The marshmallow needs to be used right away once it is made, so before you begin to mix it, get everything ready to assemble the cake. Working one cake layer at a time, scoop 1 cup of ganache into the center of the cake, and spread into an even layer—the ganache will fill the slightly sunken cavity of the cake, but continue to spread it nearly to the edges. Repeat on all cake layers, and set aside. Transfer the remaining ganache to a disposable pastry bag and cut a 1/4-inch opening from the tip. Set aside.
  4. Grease a silicone spatula with nonstick spray. Grease the inside of a disposable pastry bag with nonstick spray. You can fit it with a large round tip, or just cut a 1/2-inch opening from the end. I find it can be handy to have a pair of kitchen scissors handy—spray them with nonstick spray too!
  5. Pour 1/3 cup cool water into a medium, shallow dish and sprinkle the gelatin even over the surface. Let bloom for 5 minutes.
  6. Pour the remaining 1/3 cup water and the sugar into a medium pot. Heat the pot over medium-high heat. Stir the mixture until it comes to a boil, then stop stirring completely: Agitating a boiling sugar syrup can encourage crystals to form, which can lead to disaster. Once you stop stirring, brush any visible sugar crystals away from the sides of the pot with a damp pastry brush.
  7. Once the mixture begins to boil, fasten a candy thermometer to the side of the pot. Continue to boil until the temperature reads 245° F.
  8. Pour the syrup into the bowl of an electric mixer fitted with the whisk attachment. Add the vanilla and let the mixture cool to 220° F.
  9. While the syrup cools, melt the bloomed gelatin, either in the microwave (15 to 20 seconds) or over a double boiler, until it is fluid.
  10. When the sugar syrup has cooled, add it to the bowl of your mixer and gradually work the mixer up to medium speed. Once the mixer is running, add the melted gelatin (and any extracts, if using). Whip the sugar on medium speed until the bowl feels almost entirely cool to the touch and the sugar is opaque white and very fluffy, 4 to 5 minutes. It should hold stiff peaks. Try not to stop and restart the mixer multiple times, just keep whipping steadily for 4 to 5 minutes.
  11. While the marshmallow whips, place one layer of the cake on a cake turntable (or straight onto a cake stand). Have the other two layers ready to go.
  12. When the marshmallow is fully aerated (it should hold peaks), use the greased spatula to transfer it to the greased pastry bag. Starting in the center of the first cake layer, pipe a spiral of marshmallow, working to the outside edge. stop about 1/4 inch from the edge. If desired, toast the marshmallow layer with a kitchen torch, then top with the next cake layer. Repeat this process with another cake layer, then place the final cake layer on top.
  13. For the top of the cake, pipe little rounds/drops of marshmallow all over the top of the cake. If you want, use the scissors to help snip the end of each piped piece to help release it from the bag. Once the surface is totally covered, toast it all over with a torch.
  14. Drizzle the remaining ganache over the surface of the cake. Let the cake stand 15 minutes to 20 minutes before slicing and serving.

See what other Food52ers are saying.

  • Chiara Pepe
    Chiara Pepe
  • Mona Preeti
    Mona Preeti
  • BrettyJax
  • Nicole Lyons
    Nicole Lyons
  • Erin Jeanne McDowell
    Erin Jeanne McDowell
I always have three kinds of hot sauce in my purse. I have a soft spot for making people their favorite dessert, especially if it's wrapped in a pastry crust. My newest cookbook, Savory Baking, came out in Fall of 2022 - is full of recipes to translate a love of baking into recipes for breakfast, dinner, and everything in between!

11 Reviews

Chiara P. July 13, 2018
Because of food allergy I cannot use baking powder. What do you recommend instead to make my cake grow? Thanks!
Mona P. August 30, 2017
Will this cake hold up to being made in advance? Probably not the marshmallow, I'm sure, but can it be made, filled, and frozen? Or just the cake made and frozen in advance?
Pam S. July 30, 2016
Anyone know where I can find the cake recipe?
Pam S. July 30, 2016
Where is the actual cake recipe?
Erin J. July 30, 2016
Hi Pam - you can find it at the link listed next to the cake recipe (or here:
Ray H. June 29, 2017
Thank you! The link next to the cake isn't active for everybody.
BrettyJax July 1, 2016
Dying to make this!! Where is the actual cake recipe though?
BrettyJax July 2, 2016
Found it nvm!!
Naomi June 7, 2016
Very pretty, but looks just like the one in the Smitten Kitchen cookbook from a few years ago
Nicole L. June 5, 2016
This is over the top/outrageous. Does it need to be 3 layers? Maybe so, uh? For the full effect.
Erin J. June 8, 2016
You could absolutely make it with just one layer - or two! It would still be yummy!