28 April 2013

Campfire Cake

In the UK it may not be traditional to pair marshmallows with chocolate and biscuits to make s'mores, but for the purposes of this cake let's just say we do. In the heat of a self-imposed sugar ban, my sugar deprived mind started whirring, and the concept of this monster of a cake was born.

As with most cakes that I plan for a while before actually making, in the beginning this cake was no more than a vague idea for something involving marshmallow fluff and chocolate buttercream, but over the past few weeks the idea developed: the marshmallow fluff would be toasted for the toasted marshmallow campfire feeling; I would use probably the best chocolate icing ever, chocolate French buttercream; the cake would be a chocolate cake.

Finally, yesterday I made it. Campfire Cake is nine inches and three layers of chocolate cake, sandwiched with toasted marshmallow fluff, chocolate French buttercream and mini marshmallow, then smothered in more chocolate buttercream and piled with more mini marshmallows. I told you it was a beast!

Beasty as it is, I had some help in reducing the sugar high you might expect after eating something like this using Truvia Baking Blend*. I've been a big fan of Truvia, which is a calorie free sweetener made from the stevia leaf, ever since I was sent some to sample last summer. Sugar plays an important role in baking though, so Truvia Baking Blend combines the sweetener and traditional cane sugar so that the structure of your cake won't be compromised in exchange for looking after yourself. It worked really well in this cake, and I can't taste any difference to a normal cake. The packaging even comes with a handy conversion chart; because Truvia is three times sweeter than cane sugar, you don't need to use as much as you normally would.

This would make a great cake for parties, and could even be served at a summer barbequeue in homage to its name sake. If you'd rather use cane sugar, just substitute 200g caster sugar for the Truvia. The cake may look great, but it doesn't take very long to make. While the cake bakes you can make the icing, then all you have to do is wait for the cake to cool before you decorate it.

For the cake

  • 200g Butter
  • 150g Plain Flour
  • 50g Cocoa Powder
  • 100g Truvia Baking Blend
  • 1 Tsp Baking Powder
  • 3 Eggs
  • 50mL Milk
For the chocolate French buttercream
  • 12 Egg Yolks
  • 120g Caster Sugar
  • 250g Good Quality Butter
  • 50g Cocoa Powder
  • 1 Tub Marshmallow Fluff (Approx 200g)
  • 1 Packet Mini Marshmallows
  • Preheat the oven to 160C/140C fan and line three 9" cake tins with baking parchment.
  • To make the cake, cream the butter and sugar together until light and fluffy. Beat in the eggs one at a time until the mixture is smooth.
  • Sieve the flour, baking powder and cocoa powder into the cake batter and fold in until well combined. 
  • Add enough milk to give a soft dropping consistency, then divide the batter between the cake tins and bake in the oven for 22 mins, or until a skewer comes out clean.
  • Meanwhile make the French buttercream: prepare a bain marie or 'double boiler' by placing a bowl over a saucepan filled with a small amount of hot water. Make sure that the bottom of the bowl doesn't touch the water.
  • Place the egg yolks and sugar in the bowl and place the saucepan over a medium heat. Whisk the egg yolks constantly with a fork until they start to steam, then pour them into a mixing bowl.
  • Whisk the yolk mixture with an electric whisk until it doubles in size.
  • Chop the butter into small cubes and place into a microwaveable bowl. Microwave on the defrost setting, checking every 30 seconds until the chunks are soft enough that they can be cut in half without applying any pressure to a knife.
  • Whisk the cubes of butter, one at a time, into the egg yolk mixture until it is thick and glossy.
  • Add the cocoa powder and whisk until well combined.
  • Transfer the marshmallow fluff to a heatproof mixing bowl, and place under a grill that has been preheated to a medium heat. Let the fluff brown, then remove it and stir before placing back under the grill. Repeat this a few more times, until the marshmallow fluff tastes like toasted marshmallows (yes, you'll have to taste some...)
  • Once the cakes have completely cooled, place one on your serving dish and smear half of the marshmallow fluff over the top. Follow with the buttercream, then sprinkle with mini marshmallows before placing another of the cakes on top. Repeat the process. 
  • Once the third cake is on top, smooth the buttercream over the top and sides in a thick layer. Pile the marshmallows on top (I take a handful, then hold them in both hands. I then move my hands close to the centre of the cake and open them from the bottom so that the marshmallows have no choice but to pile up.)

My one problem with this cake is that the marshmallow fluff did not live up to expectations. Next time I think I'll just use regular marshmallows, as they will keep their thickness and will take up a better toasted flavour.

I'm entering this into We Should Cocoa's marshmallow challenge, which is hosted by Rebecca at BakeNQuilt and is run by Choclette at Chocolate Log Blog. You've got until the 25th if you want to enter.


*I was sent some Truvia Baking Blend to test out, but all views are my own.


  1. I frigging love s'mores. I went to American for the first time last year and bought two boxes of graham crackers for s'moring! This cake looks amazing, I'm going to have to try it. I'm going to daydream about it all day now ;)

    1. I went to America when I was 2 so remember nothing, but have always wanted to try those! Glad you like the cake.

  2. Wow. This looks amazing! I'm also probably going to spend the afternoon dreaming of cake and smores.

    1. Thanks Craig! Doesn't sound like the worst way to spend an afternoon, to be fair.

  3. This is my type of cake, I pair chocolate and marshmellows when making my Rocky Road cakes.

  4. That looks so deliciously gooey and chocolatey! Thanks for entering We Should Cocoa this month.

  5. Sounds amazing and the cake sort of looks like a bonfire, which is very clever. I really must track down some of this marshmallow fluff I keep hearing so much about. Thanks for entering We Should Cocoa :)

    1. Thanks Choclette! I hadn't thought about it looking like an actual fire before, but I'm glad you like the look. I found mine in Morrisons so I think it's quite easy to find these days.


Did you try this recipe? Let me know what you think! Comments are always appreciated. Unless they are spam.