Striped Halloween fault line cake

Get into the spooky spirit with this eerie-sistible striped Halloween fault line cake tutorial by Zoe Burmester...

Striped Halloween Fault Line Cake Image credit: Zoe Burmester
Brought to you by Zoe Burmester

“If you can't make a black cake for Halloween, when can you? In this tutorial I have taken a few different techniques and thrown them together to form this striking striped fault line cake, coated in dramatic black for a glamorous take on the Halloween party table” - Zoe Burmester.


  • When working with buttercream cakes in this way, remember the fridge is your best friend! I always chill the cake in between each step which makes it neater to work on as it avoids spreading any mess or blurring colours. 
  • If you don’t want to create a striped interior, simply give your cake a coat of pink buttercream for the first layer and go crazy with the sprinkles for an alternative and simpler fault line finish. 
  • In an effort to avoid the traditional orange and black I thought it would be fun to swap in hot pink, but by all means make this cake your own by swapping in lime, orange or purple and using your own choice of sprinkles. 
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You will need


  • 2x 6in cakes, stacked as double barrel, 8in high in total
  • American buttercream (see recipe below)
  • Black and hot pink oil colours (Colour Mills)


  • 1x 8in presentation/Masonite cake board
  • 1x 6in cake card
  • Cake turntable
  • Large flat spatula
  • Offset spatula
  • Long bench scraper
  • Scalloped or tooth edge bench scraper
  • Piping bags
  • Open star large and small piping nozzles ( I used Jem 1M and Wilton 32)
  • 4cm diameter circle cutter
  • Assorted small sprinkles in black, silver and purple
  • Lime green rod sprinkles
  • Eyeball sprinkles
  • Pink choco ball sprinkles

American buttercream (enough to fill, cover and pipe this cake)

  • 500g soft unsalted butter
  • 1kg icing sugar (sieved)
  • 130 - 150ml whole milk (room temperature)
  • Flavour extract of your choice


For the American buttercream

Beat the butter in a stand mixer with the paddle attachment for about ten minutes until it is really light and much paler in colour.
Slowly add in the sieved icing sugar, a third at a time. After each addition, beat the buttercream for a further five minutes before adding in the next third. Scrape the sides and bottom of the bowl to make sure all the butter is evenly combined.
Add in your extract of your choice and combine.
Finally with the mixer turning slowly add in the whole milk tablespoon by tablespoon until you reach a soft spreadable consistency. You may not use the whole amount.

To decorate

Stack, fill and crumb coat your cake, making sure your cake is placed on a 6in cake card for support. Place in the fridge and prepare your buttercream. Divide the buttercream into a 60/40 ratio in two bowls. Colour the larger amount with black and the smaller amount with hot pink.
Place your chilled crumb coated cake onto a presentation board, securing in place with melted chocolate or royal icing. Place the cake on a turntable to make it easier to work on. Now give the cake a generous coat of buttercream on the sides (about 1cm thick).
Take your long bench scraper and hold the scraper vertically against the side of the cake with one hand, use your other hand to turn the turntable and glide the scraper around the sides of the cakes to smooth out your finish. Make sure the scraper is sitting flush on the cake board so you have straight sides at all times. Place the extra buttercream back in the bowl. Once you are happy with the sides, hold the scraper flat across the top of the cake and swipe across to flatten and neaten the top. Don’t worry if you can still see the crumb coat on the top as we will be using more buttercream later.
Place the cake in the fridge for about ten minutes to allow the buttercream to firm up a little. This makes the next stage neater. Take your scalloped or ridged bench scraper and in the same way as before, place it vertically next to the cake making sure the bottom is level with the cake board. Push the scraper gently into the buttercream and slowly turn the turntable whilst holding the scalloped scraper against the buttercream.
Go round once and place excess buttercream back in the bowl. Clean the scraper and then go over the same ridges again until you have clean demarcated stripes around the cake. Focus on the middle section of the cake as we will be covering the top and bottom with another buttercream layer. Once you are happy, place the cake back in the fridge to firm up (about 30 minutes).
Place some hot pink buttercream into a piping bag and snip the end off. The opening should be as wide as each ridge. Carefully pipe a line of pink icing in each indented ridge.
Don't worry about the top and bottom ridges as again these will be covered.
Take your clean long bench scraper and hold in the same way as before. You want to carefully swipe around the cake as you turn it on the table.
Go slowly, wiping the scraper clean after each swipe. You will need to go around the cake about three or four times until the stripes have evened out. Be careful not to take away too much or the colours will start to bleed into each other and you may lose the striped effect. Place the cake back in the fridge until it is really firm.
While the cake is chilling, organize your sprinkles. You can choose whatever you like here, but try to get a combination of sizes and shapes. Eyeball sprinkles are easily found in supermarkets and the rods and larger choco balls are readily available online at cake decorating stores. You could even choose to buy a pre-mixed Halloween sprinkle set.
Take the chilled cake out of the fridge and place on a paper towel or greaseproof paper (this allows you to collect the sprinkles after). With a gloved hand, gently push the smallest sprinkles you have on around the base of the cake (we will put the bigger sprinkles on later). Work your way around the cake until all are pushed in. Collect any loose sprinkles and re-pot them for another time.
It is imperative that your striped cake is chilled well and hard to the touch before you start this stage. For the fault line, take the black buttercream and use an offset spatula to apply. Place the cake back on the turntable and start by applying a layer of buttercream to the top of the cake. Now add buttercream to the top lip of the cake - only going down 2in or so. Apply the same thickness of buttercream to the base of the cake - again about 2in high, carefully trying not to disturb the attached sprinkles.
Go back and neaten the black buttercream by carefully swiping it round with the long bench scraper. Do the sides first before you flatten the top. Always hold the scraper perpendicular to the cake - this way you can see if there are any gaps or unevenness in the buttercream. For example, in this photo you can see that the bottom layer of buttercream is thinner than the top. In which case apply a little more buttercream to even it up and swipe again to smooth.
Now you can go back in and using tweezers or your fingers, place the larger sprinkles in a random way amongst the small sprinkles.
Use a paper towel to carefully clean the edges of the Masonite board to remove any unwanted buttercream.
Place the cake back in the fridge and place the remaining buttercream into two piping bags with open star nozzle tips in the base. I used the large open star for the pink and the smaller nozzle for the black.
Take the chilled cake out of the fridge and use a 4cm circle guide as a piping guide. Press the circle cutter gently about 1cm from the edge of the cake. Continue to press circle marks all around the top of the cake. This will help ensure all your pipes swirls are the same size.
To pipe the pink swirls, place the piping nozzle in the centre of one of the circles. Slowly squeeze the piping bag to start the swirl in the centre and then swirl round to form a circle - as you come back to a full circle, lift the bag and continue the spiral up to create another layer and more height. Finish the spiral in the centre, lifting the piping bag directly and vertically up to finish. Repeat on all the circles and you should find that they are all equal in size and will touch each other side by side.
As a final touch, add in some black mini swirls between each pink swirl. Hold the piping bag vertical in the place you want to pipe and squeeze the icing to the size you want and then lift up to finish. Repeat around the cake.
Finally, finish by adding in two rod sprinkles and an eyeball to each pink swirl, along with alternating colour choco balls on the black swirls.
Last updated 7 months ago

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