Heston Blumenthal’s popping-candy chocolate cake

Posted on July 7, 2008 by Aun

Ever since returning from Barcelona, I have been slightly obsessed with peta zeta, or as we say in English, pop rocks. It’s Oriol Balaguer‘s fault. When we were in Spain, one of the must-visit places on my wife S’s itinerary was Balaguer’s boutique. She’s been slightly obsessed with this genius chocolatier ever since a pastry chef friend gave her Balaguer’s cookbook as a present some years back. Balaguer’s Barcelona boutique is a very small, chic corner space, located in the middle of a wealthy residential neighborhood. (It is also just around the corner from the showroom of Tresserra, an amazing Spanish furniture brand I am currently in love with but cannot afford — and probably won’t be able to for decades to come.)

As you can imagine, we tried many of Balaguer’s chocolates and even some of his pastries. Everything was delicious, but one thing in particular blew me away — his pop rock filled chocolate truffles. These were simply fabulous, not just because they were made with the very best chocolate but because they were fun. Really fun. I hadn’t eaten pop rocks in years. In fact, I wasn’t even aware that these effervescent candies were still being made.

Pop rocks, for those of you who have never had them (and I was amazed to discover that one of my colleagues and a close friend were among those unfortunate few), is a carbonated candy that releases carbon dioxide when popped into one’s mouth. The candy pops and sizzles on the tongue, which makes your whole mouth tingle in the most delightful way. One of the most amusing facts about this candy is that for some strange reason, back when it was really popular, some freaks started spreading a rumour that if you ate pop rocks and drank Coke at the same time, your stomach would explode. Obviously, this isn’t true, but countless kids did try and test the theory for themselves.

The Balaguer peta zeta truffles were so outstanding that the day before departing Barcelona, S and I went back to the boutique in order to purchase several boxes, for ourselves and a few friends. Of course, these lasted only a week or two. Since then, I have been sporadically doing research of how we home-chefs can play with pop rocks in our own desserts.

The first thing I had to do, of course, was get my hands on some pop rocks. Thank the gods for eBay. A couple clicks and within a week, a carton of 36 packets of pop rocks (half of them strawberry flavoured and the other half watermelon) was delivered to my door. As you might imagine, there aren’t a whole lot of interesting recipes out there. Most of them were the “sprinkle your pop rocks on your finished dessert” variety, which to me seems like a bit of a culinary cop-out. Then I found Heston Blumenthal’s “popping-candy chocolate cake”, a chocolate mousse cake built over a hazlenut and pop rock base. The recipe seemed promising and relatively easy to make.

The pop rocks are mixed into melted milk chocolate. This in turn is mixed into a hazelnut paste and pressed into the bottom of a ring mould (Heston suggests making one cake using a 12cm ring mould but S and I used 9cm moulds and discovered that his recipe provides enough to make 3 smaller cakes). This becomes the base of the cake. From the pictures, you can tell that we really should have made the base quite a bit thinner (but hey, this was our first attempt).

The mousse was rich and tasty. Very delicious in fact. But when chilled, it became dense and a little too heavy for our tastes. S and I have decided that if and when we make another popping-candy cake, we’ll use a light gelatin-based mousse a la Hidemi Sugino (i.e. a Japanese style mousse cake).

That said, the cake was fun to make and even more fun to eat. We ate one, gave one to our colleagues, and another to a friend (the one who had never had pop rocks before). I have 26 packets of pop rocks left so I plan on experimenting a little more. Here’s the recipe in case some of you can get your hands on some pop rocks and want to try the recipe also.

Heston Blumenthal’s popping-candy chocolate cake

For the popping-candy base
85g whole hazelnuts
40g milk chocolate
2 tsp mixed spice
100g popping candy

For the chocolate mousse
350g dark chocolate
400ml double cream
Pinch of salt

For the chocolate glaze
20g chocolate (same type as for the mousse)
120ml water
8 whole coffee beans
Couple of pinches of salt
30g cocoa powder
70g unrefined golden caster sugar

To make the base, preheat the oven to 180C/ 350F/Gas Mark 4 and roast the hazelnuts for about 10 minutes until lightly coloured. Blend to a paste in a food processor, then set aside. Melt the milk chocolate in a bain-marie (a large basin over a saucepan of simmering shallow water — take care that the water does not touch the basin) and stir in the ginger spice and popping candy. Next, fold in the hazelnut purée. Place the 12 cm ring mould on a serving dish and gently press in the base mixture to a depth of about 1cm. Refrigerate for at least 2 hours, until hard.

To make the mousse, chop the chocolate into small pieces and place in a metal bowl. Bring 150ml of the cream to the boil in a small saucepan. Pour it over the chopped chocolate and stir extremely gently until all the chocolate has melted, watching carefully to ensure it doesn’t take on a granular texture. Add the salt to taste. Once the chocolate cream has cooled to room temperature, lightly whip the remaining 250ml cream to soft peaks, but do not overwhip. Fold into the chocolate mix. Pour over the base in the ring mould and place in the fridge to set for two hours.

To make the glaze, chop up the chocolate and set aside. Place the water, coffee beans and salt in a pan, whisk in the cocoa powder, then set over a medium heat and simmer for about 3 minutes. Meanwhile, put the sugar in a small pan and melt over a medium heat. Unrefined sugar will caramelise quickly, so keep an eye on it; when it does, pour over the coffee and cocoa mix — stand back, as it will bubble and spit. Beat in the chopped chocolate and, when melted, pass through a fine sieve. When cool, but still liquid, pour over the mousse to your preferred depth and return the cake to the fridge to set.

To serve, run a hot knife around the inside of the ring before removing the cake. When slicing it, again make sure the blade of the knife is nice and hot.

About Aun Koh

Aun has always loved food and travel, passions passed down to him from his parents. This foundation, plus a background in media, pushed him to start Chubby Hubby in 2005. He loves that this site allows him to write about the things he adores--food, style, travel, his wife and his bouncing baby boy!

What Others Are Saying

  1. Ahna July 8, 2008 at 12:10 am

    Is there any way to download your recipe pages to print them?

  2. Mei July 8, 2008 at 12:16 am

    ooh what an inspiration – i have a soon to be 11 year old and he’ll be hte envy of his mates with this for a birthday dessert!

  3. Mei July 8, 2008 at 12:40 am

    Did the pop rocks actually retain the effervescent actions after being incorporated into the cake?

  4. Kitt July 8, 2008 at 1:01 am

    What a glamorous use for a silly candy!

    (I remember when Pop Rocks first came out in a few test markets. All of us kids tried desperately to find someone, anyone, who could send us some! Oh, that was a long time ago.)

  5. My Sweet & Saucy July 8, 2008 at 1:50 am

    Love this! You cake looks and sounds delicious!

  6. L July 8, 2008 at 3:14 am

    I loved pop rocks as a kid! I haven’t had them since I was little. I remember we used to be scared of accidentally swallowing a few (it wasn’t very pleasant). I’ll be sure to try out Balaguer’s boutique when I am in Barcelona next month!

  7. Julie July 8, 2008 at 3:53 am

    How fun! This post made me giddy. =)

  8. steamy kitchen July 8, 2008 at 6:41 am

    I let my kids have PopRocks for the first time in their little kiddie lives and the expressions on their face was priceless! I don’t know if I’m brave (er..really, talented) enough to make desserts with poprocks, but certainly admire yours!

  9. Thermomixer July 8, 2008 at 10:39 am

    Thanks for the recipe. My partner purchased lots of Pop Rocks after Oriol visited Melbourne in March. A friend gave us some of his truffles to try & so we have being experimenting. No recipes with them in the Thermomix yet but will let you know when we do.

  10. Vanessa July 8, 2008 at 4:40 pm

    Thanks for the recipe, I am dying to give it a shot!

    By the way…try pop rocks with Coca Cola….hahahaha the explosion in your head is quite thrilling :)

  11. Annette July 8, 2008 at 7:31 pm

    Ooh, that sounds like so much fun. Now I have to get pop rocks and play! Btw, is the Sugino book published in English and do you know where I can buy a copy?

  12. denise July 8, 2008 at 11:40 pm

    this is so interesting! definitely a must-try recipe.. now i just gota get those pop rocks.

  13. Haley July 9, 2008 at 1:44 am

    I’m Haley, Key Ingredient’s Chief Blogger. We would like to feature this recipe on our blog. Please email haleyglasco@gmail.com if interested. Thanks :)


  14. Chicken Fried Gourmet July 9, 2008 at 8:31 am

    you can buy Neutral flavor pop rocks at http://www.chefrubber.com and incorporate any flavor you like :) Foie Gras anyone???

  15. Ari (Baking and Books) July 9, 2008 at 9:16 am

    This is a delightful post! Pop rocks are a popular ingredient in chocolate candy bars in Israel, but I am in love with this cake. It looks divine and the mischievous side of me would love to serve it at a posh party without telling guests that pop rocks were in the cake! Hehe.

  16. Stephanie July 9, 2008 at 11:49 pm

    That is such a cool idea! How fun!

  17. Johnna Knows Good Food July 10, 2008 at 5:40 am

    This cake and this blog are awesome!!

  18. Y July 11, 2008 at 9:08 am

    What a fun way to enjoy cake :) I’ve used poprocks as a garnish for an ice-cream bombe before. It was meant to be a play on the whole bombe/explosions-in -the-mouth thing.

  19. Dee July 11, 2008 at 11:57 am

    I’ve been lurking in your kitchen for ages, nicking recipes and living vicariously through your travels, so I figured it was time to say hello.

    I love pop rocks, and after reading this I’m desperate to get my hands on some so I can play too.

    Also, I made the Vietnamese Caramelised Ribs and loved them. Then I tried your Mentaiko pasta and fell in love again. Now, I’m pretty convinced that anything I pinch from your recipe stash is going to rock!

  20. sooishi July 12, 2008 at 5:53 pm

    i absolutely love the idea! In Switzerland at easter we can find some chocolate eggs with somme poppy candy insinde of them…
    Last time i ate something similar it was chez Denis Martin, a chef near the lake of Geneva.
    Thank you for the recipe i can wait to try!

  21. Duncan | Syrup&Tang July 12, 2008 at 9:15 pm

    I was reminded of pop rocks only recently when I tasted a macaron creation called Krac Krac at Pain de Sucre in Paris. Lots of fun in the surprise, and of course a wave of kiddie memories. Nice to see this is a culinary craze!!

  22. Melanie D July 14, 2008 at 3:49 am

    It’s my first time to visit your blog, and what can i say? you easily impressed me. All my senses were trying to rebel against my diet when i saw that Heston Blumenthal’s popping-candy chocolate cake!

    I think i have found another excuse to stay away from my diet. lol. Thanks, for sharing this great recipe. You may want to try this recipe http://www.foodista.com/2008/06/23/perfect-tart-crust/

    I tried this just recently and the outcome is oh so delicious!

  23. Allen July 20, 2008 at 2:25 am

    Wow – what a great idea for Pop Rocks! I loved them as a kid and it’s good to see an adult use for them too :-)

  24. Gift Bird July 21, 2008 at 1:46 pm

    And I was doing so well this summer. I think you just ruined my diet. eBay you say…I’m there :)

  25. Mab July 23, 2008 at 11:09 am

    another alternative to experience this choc and pop sensation would be to grab a bar of cadbury’s popping candy from Candy Empire.


  26. Holy July 28, 2008 at 1:43 pm

    Such a strange combination…pop rocks and chocolate cake. Yet I’m sooo intrigued!!

  27. Susan at Black eyed susans kitchen July 28, 2008 at 11:20 pm

    Would you know if pop rocks can be incorporated into a basic chocolate chip cookie recipe? Do they retain their explosive nature? This would be a winner at the school bake sale. Susan

  28. sam August 12, 2008 at 1:40 am

    FYI if you accidentally type in the authentication code incorrectly it deletes your comment and you have to type it in all over again. Kind of frustrating if you’ve just typed in a long comment.

  29. sam August 12, 2008 at 1:49 am

    In San Francisco Elizabeth Falkener has also incorporated pop rocks into the menu at her latest restaurant, “Orson” in an appetizer dish called: “parmaggiano pudding, pepper jam, cocoa nib explosion”. It’s a light and unusual dish that never fails to make everyone who tries it for the first time, smile. It certainly brings some unabashed fun back into dining out!

  30. Lorraine E August 14, 2008 at 9:36 pm

    The cake looks amazing, and I love the fact that it is made of pop rocks! You’d never think something as sophisticated looking as that would be an ode to kid’s candy :)

  31. Robin August 15, 2008 at 8:31 pm

    Oo! How fun to give this cake to someone who never had pop rocks before – I can just imagine their face!

  32. Hillary August 20, 2008 at 5:24 am

    You have no idea how excited I am about this! Thank you for this recipe! I have been obsessed with chocolate bars with pop rocks for awhile but never did I realize my boundaries could have been expanded! SOOO excited!

  33. brenna August 22, 2008 at 12:45 am

    Maybe a bit of a cop out, but they are fun to rim a cocktail glass with.

  34. Alana August 23, 2008 at 6:16 am

    I recreated this gem Alaska style for a book group where we were discussing Afghanistan. This cake blew them away! Thanks for the great idea and recipe!

  35. Personalized Baby Bags September 21, 2008 at 5:42 am

    PopRocks and chocolate cake! Davine. I think I might have to try this out just for the heck of it. Sounds really delish!

  36. Jennifer Rucinski October 10, 2008 at 2:07 am

    on the list of ingredients it says mixed spice, in the directions it says ginger spice- which is correct and what is “mixed” spice?

  37. boyce October 16, 2008 at 2:57 am

    Your pop rocks comments reminds me of a dinner I had in Beijing at the Blu Lobster, where more than a few of the dishes gave that sensation, including a small plastic bag of chocolate mousse diners put in their mouths and then break with their teeth, with the ensuring sensation being a pop rocks one.

    Cheers, JB

  38. Rachael November 8, 2008 at 3:09 am

    Thanks for the information…I bookmarked your site, and I appreciate your time and effort to make your blog a success!

  39. ann November 20, 2008 at 10:31 am

    Heston Blumenthal is coming to Melbourne along with other awesome chefs from the UK like Sat Baines, and Thomas Keller from the US. Pretty worth it to attend the dinners considering that you can save the cost you’d need to pay to go to different parts of UK and the US minus the cost to head to Melbourne. Would love it if you can head there and blog about it! I’m bummed out that I can’t go…

  40. patrick March 23, 2009 at 12:52 am

    I love the fork that’s in the photo with th popping candy cake. Is it part of a set, are they available to buy?
    Many thanks,

  41. anoymous May 15, 2009 at 9:10 pm

    well i was just woundering if you ate too much of this would you explode

  42. msmarmitelover January 21, 2010 at 7:58 am

    Hi, I too have tried this recipe and I agree with you. The proportions of the hazelnut base are wrong for the size mould and the chocolate mousse is too heavy and dense. Heston suggests this as a good cake for a children’s party. It’s far too dark and intense for children.
    This is not one of Heston’s best….needs work.

  43. olga November 10, 2010 at 11:53 am

    how did you get the pop rock not to deactivate, did they still pop when you eat the cake? every time i try to use them with something they pop as soon as they touch something moist.
    also what spice mix are you talking about, thanks! i am really excited to try this

  44. Michael September 15, 2011 at 5:53 am

    That cake looks totally over the top- looks like Death by Chocolate AND Pop Rocks!
    Great photos- what kind of camera did you use?

  45. Lan January 22, 2012 at 1:54 am

    I tried to create this and had problems: the moment I added my candy pop to the melted chocolate, they all popped instantly. do you have a suggestion for this please?
    thank you!!

  46. jas March 18, 2012 at 1:36 am

    i thought the cake would be bigger but the recipe above says a 12cm ring, are you sure its not 12 inches? 12cm diameter would be quite small.

  47. S March 20, 2012 at 11:00 am

    Dear Lan, it’s kind of inevitable, they do pop as you fold them in. But we found that they still worked in the assembled cake. Dear Jas, the original recipe did say 12cm. We made three 9cm ones.

  48. Tara Leong June 22, 2012 at 8:36 pm

    Looks devine, Have you made the Hidemi Sugino yet? I’m interested to see what that is like!

    • Aun Koh June 22, 2012 at 10:25 pm

      Funny you should ask. We have a Hidemi Sugino post scheduled for early next week.

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  52. Claire November 7, 2012 at 12:31 am

    How would you suggest making this for 20+ people? You can only get the rings in sets of around 2 ):

    • S November 7, 2012 at 8:20 pm

      Hi Claire, Yikes, that’s a lot of people to make dessert for! I haven’t tried this myself, but you could possibly double up the recipe and see if it will fit into a standard cheesecake tin. And make as many of those as you need for more than 20 people. I personally wouldn’t want to be stuck making over 20 individual portions! But if you do, I would make each one a little smaller. It was a lot for one person to eat. And it would be easiest to unmould if you line the ring with an acetate sheet.

  53. sapna December 27, 2012 at 10:12 pm

    I added biscuits to the base, and used nearly double the amount of cream in the mousse, plus some icing sugar (the mousse was far too rich and a little bit too bitter!) The glaze was difficult to make (the sugar solidified as soon as it hit the water/coffee/chocolate mix). I would make it again, but with some changes.

    • S December 29, 2012 at 1:40 pm

      Thanks for the feedback, Sapna.

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  55. Bonnie December 17, 2013 at 2:56 am

    We’ve made this countless times now and it’s awesome every time!! I’m, making it next week for BF’s birthday with cherry topping instead of the glaze! As far as other pop rocks recipes… we tried an awesome mixed drink at Dylon’s Candy Bar in NYC. They put the candy in the bottom of the margarita glass and when you pour the drink in it explodes! Pretty fantastic. There is still a little fizzing when you drink it!

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