Sprinkle Fault Line Cake Tutorial

how to make a sprinkle fault line cake

There’s a serious sprinkle trend happening on Instagram, and I’m not even sure who came up with it! I’ve been marveling over sprinkle fault line cakes for weeks now, and I finally got the chance to try it for myself. I was so excited to use the technique with the Vintage Rose Gold sprinkle mix by SprinklePop because the sprinkles alone are stunning, but the fault line style really makes them pop! I just love the way they look peeking through that buttercream:

sprinkle fault line cake tutorial
sprinkle fault line cake with sprinklepop sprinkles

Pretty, right? Before I act like an expert and show you how to create this sprinkle fault line cake, allow me to admit that this was my second attempt. The first go at this technique did not end well at all. The sprinkles got in the way of my smooth buttercream, my fault line was too tiny, and I basically ended up with a ripply, sprinkled mess. Thankfully, I learned some valuable lessons in my first attempt and I can tell you how to avoid cake tragedies like that!

vintage rose gold sprinkles by sprinklepop
fault line cake decorating tutorial

Now, I can confidently say I’ve got all the details of how to make a failproof sprinkle fault line cake below. Here’s a quick video of the process before you read all about it:

You Will Need

Step 1: Separate The Sprinkles

To prepare for your beautiful sprinkle fault line cake, first divide the sprinkles into two separate bowls: one for the jimmies and smaller sprinkles, and one for the large spheres and dragees.

rose gold sprinkle mix by sprinklepop

If you’re planning on coloring your buttercream, now is a good time for that too! For this rustic rose color, I used a combination of Americolor Dusty Rose, Peach, and Maroon.

Americolor Dusty Rose buttercream

Step 2: Frost Only The Middle Of The Cake

Place your crumb coated cake on a turntable and frost a thin layer of buttercream around only the middle of the cake. Then, smooth it with your icing smoother.

frosting a fault line cake

This will become the middle of the fault line, where the sprinkles go.

Step 3: Apply The Small Sprinkles

Place a baking sheet underneath your cake turntable to catch any sprinkles that fall (this part can get messy!). Then, add only the jimmies and smaller sprinkles to the newly frosted portion of your cake.

creating a sprinkle fault line cake

By leaving the larger sprinkles out of this part, you will prevent them from getting in the way once you frost the buttercream fault line. That was the biggest takeaway from my first time trying this technique. Smaller sprinkles make it easier to achieve a smooth, flawless fault line. Don’t worry though, we’ll add the larger sprinkles in toward the end!

Step 4: Frost The Fault Line

Frost and smooth the top of the cake, then add buttercream to the top third and bottom third of the cake, making sure you stop wherever the sprinkles begin. Feel free to overlap the sprinkles in some areas, but try to keep most of the sprinkles exposed. Also, make sure that the layer of buttercream you add is thicker than the layer of sprinkles. This way when you go to smooth it, your icing smoother will glide over the buttercream without dragging the sprinkles along with it.

buttercream fault line cake

Next, smooth the buttercream with your icing scraper to create even sides without touching the sprinkles.

smooth buttercream cake with sprinkles

When your sides are looking smooth, use your angled spatula to create sharp edges around the top of the cake by swiping any buttercream from the outer edge toward the top center of the cake.

sharp edges buttercream cake

Once your fault line is looking perfect, chill the cake in the refrigerator for about 20 minutes to let the buttercream firm up before moving on to the next step.

Step 5: Add In The Large Sprinkles

Now that the buttercream is nice and set, it’s time to add in the rest of this beautiful sprinkle mix! Add all of the large sprinkles you separated out in Step 1 to the sprinkled portion of the cake.

Adding sprinkles to fault line cake

Continue adding sprinkles until the fault line looks dazzling.

Step 6: Paint The Edges (Optional)

To complete the look, use a small food-grade paintbrush to paint some Gold Edible Art Paint onto the edges of the fault line. As an alternative to Edible Art Paint, you could use gold foil, gold luster dust mixed with a little vodka, or whatever your jam is when it comes to an edible gold look!

Gold edible art paint

And voila! This sprinkle fault line cake is so eye-catching. I love this technique now that I know a few tips and tricks to getting it just right!

fault line cake with sprinkles
Rose gold cake by Sugar and Sparrow

I hope you feel a little more confident with your sprinkle fault line cakes now that you know a thing or two. Be sure to try it with your fave SprinklePop mix! And if you found this tutorial helpful for your cake decorating session let me know by tagging me on Instagram. I love to see what you’re caking 🙂

Disclaimer: I was compensated by SprinklePop for my work of creating this project, styling, filming, photographing, and writing about their products. As always, all opinions are honest and my own. Thank you for supporting brands that support Sugar & Sparrow.


  1. Michele Mallory-Davidson

    Ahhhh, I never would have thought to separate the big bits out, brilliant! Beautiful cake, love the color and the sprinkles are amazing!

    • Yes, Michele! That was the biggest lesson I learned in my first attempt. Thanks for the kind words about my cake and I hope you get a chance to try this!

  2. That looks amazing!! You are a wizard of all things beautiful!
    I’m inspired and need a piece RIGHT NOW!!

  3. This is so pretty and festive. Thank you for all the tips and tricks. ordering my sprinkles today 🙂

  4. Wow, this cake is beautiful, and the instructions are really easy to understand. Thanks for including the bit about making the buttercream thicker above and below the fault line – I never would have thought of that 🙂 If I ever try a fault line cake, now I’ll know where to go!

    • Yay, Jan! I hope you have fun with your fault line cake and find the tutorial helpful! Cheering you on 🙂

  5. Awesome Whitney, thanks for sharing. I am going to try it this week.

  6. I also didn’t know fault line cakes were a thing until this weekend. I made one following another recipe but yours looks so much simpler! well done

    • Hi , I will be making a fault line cake for my anniversary this Wednesday.i love your tutorial thks.

  7. Thanks so much for this, it seems the easiest so far‍❤️‍‍

  8. What size are the cakes and how many did you use? I’m planning on making this for my birthday.

  9. Loved the way it looks, very helpful managed to get it right the first go round thanx.

  10. This is beautiful! Thank you for the tutorial — it was very helpful. Once question — how do you get your buttercream so smooth? Mine had a bunch of air bubbles in it.

    • Hi Mona! To get rid of airbubbles, I mix my buttercream on low for about 30 seconds to push out as much air as possible, then follow the steps in this tutorial: https://sugarandsparrow.com/how-to-frost-a-cake/ basically, I frost the cake as smooth as possible, put it in the fridge to firm up for about 20 min, then frost another thin layer to fill in any air bubbles or imperfections.

  11. Sharon Coelho

    Hi Whitney, This is a stunning cake. Thanks for sharing the tutorial. You mentioned you use all three gel colours together to frost the cake. How many drops of each did you use.

    • Thank you, Sharon! I did use a combination of those three color gels to get the frosting color. It’s mostly Americolor Dusty Rose plus a little bit of Peach + Maroon to tone it just right. I don’t ever count how many drops I use because it’s really relative to the amount of frosting you’re coloring. Instead, I would just add a few drops at a time (starting with Dusty Rose, then toning with Peach/Maroon) until the desired shade is achieved.

  12. Mary Beth Christie

    Thank you so much for posting your process. This was my first time doing this and with your help, it turned out great!!!! Thank you for sharing!!!!!

  13. First time doing a fault line cake and I followed your tutorial! .
    It was easier and harder than I thought : D Overall I was happy with the final result as was the recipient but I certainly felt the pressure whilst smoothing the icing !

    So glad I found your website as I have looked through the other tutorials and keen to give them a go as well! Thank You x

    • Yay, Faye! I’m so happy to hear that this tutorial was helpful 🙂 thank you for your kind words and I’m excited for you to try more tutorials!

  14. Kim Dunlop

    Hi Whitney, If I’m decorating this cake the day before would the sprinkles bleed into the icing? Should I store it in the fridge overnight? Thank you for your tutorial, so many helpful tips!!

    • Hi Kim! As long as you use sprinkles like the ones I use in this tutorial (ones that don’t naturally bleed), the sprinkles shouldn’t bleed into the icing. Any of the Sprinkle Pop sprinkle mixes will be perfect for this look. And yes, I usually store my decorated cakes in the refrigerator overnight to preserve all the decorating, but then bring them back to room temp before serving them.

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