How To Make A Chocolate Explosion Cake
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This Chocolate Explosion Cake not only looks amazing but also tastes as good as it looks. And is SO easy to make! This is a chocoholic, chocolate lover’s dream cake – perfect for birthdays and other celebrations!
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I made this cake for my son’s 18th birthday, and now I’m going to show you how to make a chocolate explosion cake for your *insert family member/friend here*. It’s a cake that wows guests, and is totally Instagram worthy!
There are 500+ Recipes, including more themed birthday cakes on The Purple Pumpkin Blog for you to enjoy! Please feel free to check them out too.
Chocolate Explosion Cake
I used to make and sell celebration cakes and cupcakes, and am the go-to cake maker for friends and family, some of which I’ve shared on my blog.
I actually stopped making cakes regularly a few years ago, so my cake-making skills were at an all-time low when I made this chocoholic’s dream cake for my son’s birthday.
Good thing that this cake is so easy to put together… All you need is a chocolate cake, some chocolate frosting and a whole load of chocolate bars!
Now, the reason why I have described this as the easiest birthday cake ever is that I didn’t make a thing… it was a complete assembly job, thanks to store-bought chocolate cakes, frosting, and chocolate bars.
Don’t get me wrong, if you want to make your own cake and frosting, please do. If I had more time, I would have done the same, but I didn’t.
I’ve included a chocolate cake recipe at the end of this post.
Chocolate Explosion Cake Ingredients…
I will confess that I had no plan going into this cake. I literally just bought a bunch of my son’s favourite chocolates and chocolate bars and hoped I would have enough!
That said, I will give the approximate quantities I ended up using, for a better guide to make this chocolate bar cake than my ratchet way of making it!
- 20cm/8″ chocolate cake – the height needs to be about 10cm/4″ (I stacked two Tesco large chocolate birthday cakes on top of one another, no need for support between the layers.)
- 1 can Betty Crocker Milk Chocolate Icing/Frosting (400g in the UK, 16oz in the US)
- KitKat bars (10-12, 4-finger packs)
- 40 Maltesers (2-3 regular bags) (US candy: Whoppers)
- 40 Cadbury Chocolate Buttons (3-4 treat size bags) (US candy: Candy Wafers/Melts)
- Kinder Egg (2 – just in case one breaks, if they both do… oh well, hide it with M&Ms!)
- M&M’s – your favourite kind, I used Crispy and Peanut (2-3 bags of each)
- Reese’s Peanut Butter Cups (2 x 3 cup packs)
- Kinder Bueno (2 bars)
- Cadbury Dairy Milk (2 bars) (US candy: Hershey’s Bar or Milk Chocolate Lindt bar)
- Snickers (2 bars)
- Cadbury Flake (2 bars)
- Milky Bar (2 bars) (US candy: white chocolate Lindt bar)
Ultimately you can use whatever chocolate bars/candy bars that you like! You could focus on just 2 or 3 types, or go nuts and use ALL the chocolate!
Equipment Needed…
There isn’t any real need for any special equipment to make this easy chocolate cake, so if you don’t have the things that I have listed below – don’t worry, as there are alternatives.
But if you plan on making more cakes in the future, it’s worth investing in some basic cake decorating tools.
- cake stand or a large plate
- spatula or you could use a knife (to spread some frosting on the back of the KitKat bars so that they stick to the cake)
- piping bag or plastic food bag (fill the bag with frosting, and snip off the corner for a make-shift piping bag)
- birthday age candle (optional)
Personalised Cake Toppers on Etsy
I'm currently in love with this style of cake topper that I've seen all over social media recently. I think these toppers would work so well with a chocolate explosion cake!
How To Make A Chocolate Explosion Cake
If you are making your own cake, you will need to cover it completely with chocolate frosting.
My store-bought cakes were already frosted so I didn’t need to – but I did add a layer of frosting on the top to cover the writing that was on it!
- Place the cake in the middle of the cake stand.
- Break the KitKats into two-finger pieces. I used 11 full-size (4-finger) KitKats, plus one finger!
- Spread some frosting on the back of each KitKat and start to stick around the sides of the cake. Make sure that all of the embossings is facing the same way, and that the bottoms are touching the cake stand.
I added the Maltesers and Buttons around the cake because it was a bit higher than the KitKats and I wanted to hide it.
So, if you’re going to do the same, you will need to stick them on with some frosting.
If you don’t have a piping bag, use a plastic food bag instead – just add a big spoonful of frosting, and squeeze it down into one corner. Snip off the tip and away you go!
- Squeeze a blob of icing onto each of the Maltesers, and stick to the cake on top of the KitKats.
- Squeeze a blob of icing just behind and between each of the Maltesers and gently press in the Buttons.
- Use the photo above for reference!
- Now it’s time for the fun part – making the chocolate bar explosion!
- I found it easier to work from a focal point. In my case, it was the 18 candle that I placed about a third of the way from the front of the cake, and in the center. If you’re not using a big candle like this, another focal point could be a shaped piece of chocolate like a chocolate bear or chocolate egg.
- I started towards the back of the cake, gently poking the chocolate bars into the cake, deep enough so that they would stay standing. For added support, I added blobs of frosting with the piping bag.
- Some bars I broke up into pieces, and the Snickers bar I cut in half on the diagonal. Basically, just add chocolate bars until you are happy with the way it looks!
- Use my photos as a guide.
- Place taller pieces of chocolate at the back center, and graduate out in height.
- I then split open the Kinder Eggs – one shattered completely, the other one was a lot better, and I hid the broken bottom bit with some M&M’s and added some more to sit inside the egg halves.
- I tucked in the Reese’s Peanut Butter Cups and halved one to make it look like it was stuck inside the cake. I then filled in the front of the cake with loads of M&Ms.
- And that is IT. Literally, stick chocolate bars into a chocolate cake – ta-dah! I told you it was easy, didn’t I?
Have you made this cake? Join 100+ others and share a picture of it on Pinterest! Just scroll down and tap to add a photo in the tried this pin section. I love seeing your cakes!
Celebration Dinner Ideas!
Looking for some mealtime inspiration to go with this cake? I’ve got you covered!
- Appetizer: Nachos & Guac
- Main Dish: Slow Cooker Beef Fajitas
- Side Dish: Pico de Gallo
- Beverage: Blue Hawaiian Cocktail
More Cake Recipes
If you’re looking for more cake recipes, here are some for you to check out:
- Strawberry Shortcake (Disney copycat recipe)
- Chocolate Cherry Cream Cake recipe.
- Chocolate + Peanut Ice Cream Cake
- Pineapple & Coconut Upside Down Cake
Chocolate Cake Recipe
Ingredients
- 100g unsalted butter, melted
- 250g caster sugar
- 50ml sunflower oil
- 25g cocoa powder
- 2tsp vanilla extract
- 4 medium eggs
- 100ml double cream
- 300g plain flour
- 3tsp baking powder
Instructions
- Pre-heat oven 180C/350F/Gas 4
- Grease and line an 8″ cake tin
- Place the melted butter, caster sugar, sunflower oil, cocoa powder, and vanilla extract into a mixing bowl, and beat well.
- Beat in the eggs, until well combined, then beat in the cream, until the mixture is smooth.
- Sift the flour and baking powder into the chocolatey batter, and fold in. You will find that the mixture is a bit runny, but this is how it should be!
- Pour the mixture into the prepared cake tin and cover with foil.
- Bake for 35 minutes covered, and for 25 minutes uncovered.
- When cooked, the cake should be springy to the touch, and a skewer come out clean when inserted in the middle.
- Leave to cool completely in the tin before turning out.
- Decorate as desired.
Tracy
May 16, 2022 @ 8:01 am
How early can you put the chocolates into the cake? Would the day before be ok?
Michelle
May 25, 2022 @ 9:24 am
I did mine on the morning of the party, but I’m sure the day before would be fine too – cover the cake and keep it in a cool, dry place.
Jackie
November 23, 2021 @ 5:02 pm
Made this for my 13 yr old grandson. Couldn’t get any Flakes over here in USA so used Twix instead. And Kinder eggs aren’t the same so just used extra white chocolate. Everyone was very impressed. Would gladly send a photo but not on any of the social media you mention.
Michelle
November 24, 2021 @ 3:03 pm
Thanks for emailing me your cake photo – it turned out great! The types of chocolate/candy bars doesn’t matter – it will always taste awesome!
Joanna ponsonby
April 13, 2020 @ 7:55 pm
Hi- may I just ask did you put icing In between the two cakes?
Michelle
April 14, 2020 @ 8:26 am
Hi Joanna
Because I used ready-made cakes that had frosting on them, I didn’t bother to put icing between the cakes. But you can certainly put some between the layers if you want to!
Hannah
February 17, 2020 @ 3:17 pm
Hi, I am attempting to make something similar this weekend for my husband’s Birthday. I am going to be short on time so have decided to buy a cake and decorate it like you did. You mentioned you got yours from Tesco – was it this one?
https://www.tesco.com/groceries/en-GB/products/258300895
Just wondering whether the kitkats would stick to the sides or if I would have to put extra frosting all down the sides too? Thanks!
Michelle
February 18, 2020 @ 9:36 am
That is the exact cake I used! I actually used two cakes stacked on top of each other.
It’s been a while since I made the cake, but I do believe I just slapped some frosting on the back of the Kit Kats and that was enough to stick them to the sides of the cake.
I hope this helps and please share your finished cake with me, I’d love to see how it turned out!
Julie
October 2, 2018 @ 2:42 pm
My cake has been in over for 35 & 25 mins but it is still quite wobbly in the middle? HELP
Michelle Ordever
October 2, 2018 @ 4:19 pm
Have you got the oven at the correct temperature? Have you been opening the oven a lot? There are all reasons why it might still be wobbly – just keep cooking it! Maybe place some foil on top so it doesn’t burn too much!
Lynne snowden
October 14, 2017 @ 5:02 pm
Have you recipe for the frosting please
Michelle Ordever
October 14, 2017 @ 7:28 pm
On this cake I used ready-made frosting (Betty Crocker). You can find my frosting recipe here: https://www.thepurplepumpkinblog.co.uk/red-white-60th-birthday-cupcakes/ – I always use equal measures of butter and icing sugar.
Sandra Clarke
March 4, 2017 @ 8:52 am
Love this idea thank you. My son is 18 in June so I will be attempting this but will just have to source everything which is gluten free so the Kit Kat surround is out which is a shame but I’ll think of something else.
Michelle Ordever
March 4, 2017 @ 7:37 pm
Are Matchmakers gluten free? Or what about a load of Buttons around the edge of the cake? When you make it, please share it with me on Facebook, Twitter or Instagram (#thepurplepumpkinblog) as I would LOVE to see it!