Sprinkle Fault Line Cake for Valentine’s Day

in Cakes

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This Valentine’s Day themed sprinkle fault line cake is made with homemade vanilla cake layers, simple vanilla buttercream, and loads of Valentine’s themed sprinkles!

Sprinkle Fault Line Cake Valentine's Day

If you’ve spent any time on Instagram in the last few months browsing cake photos, you would undoubtedly have come across some beautiful fault line cakes!

I was waiting for an occasion to jump on this trend, and with Valentine’s Day around the corner, how could I not?

The fault line

The fault line is just one of many cake trends that have made the rounds in the past year, especially on Instagram! If anyone knows who I should credit, let me know!

This unique trend keeps the sprinkles in the spotlight to glam and sparkle to your cake!

Sprinkle Fault Line Cake Valentine's Day

Let’s talk Sprinkles

The sprinkles make this look come to life!

I used a variety of sizes in the sprinkles around the theme of Valentine’s Day. You can choose to use a trendy sprinkle medley from suppliers like Sweetapolita, or even make your own sprinkle medley mix using a variety of sprinkles.

You only need about a 1/2 cup of sprinkles for a 4-inch cake like the recipe below.

Steps to assemble the fault line cake

I am by no means a cake expert. These are just the steps that I followed after referring to other sources, and this is the order of steps I followed to make this trend come to life!

Step #1: The Canvas – Start with a smooth and cold cake

Once you have crumb coated the cake, and put on your first layer of frosting, make sure to refrigerate the cake before moving onto the enxt step. This helps with sticking the sprinkles where they need to go, without getting mixed into the frosting!

Step #2: Separate the Sprinkles

I found that using smaller sprinkles as a base was easier to incorporate into the fault line cake. With bigger sprinkles, it’s hard to smooth on the outside layer of frosting.

Step #3: Outline your fault line

I used a bench scraper to mark where I wanted to create the outside of my fault line. Also, keep in mind to mark these points as bigger than you would initially think. The fault line will likely shrink as you smooth on the frosting.

Step #4: Stick the smaller sprinkles first

Working with a cold cake makes this step easy. To stick your sprinkles, I find it best to dip my fingertips in water before dipping them in sprinkles. It makes less of a mess, when moving the sprinkles from the bowl to the cake.

Tip: I placed the cake turntable on a baking sheet for this step to help catch any loose sprinkles. I still made a mess, but it helped!

Sprinkle Fault Line Cake Valentine's Day

Step #5: Frost and Smooth to create the fault line

Once the small sprinkles are on the cake you’re ready to frost the outside of the fault line. Pipe frosting on the top and bottom of the cake, and smooth it with a bench scraper or offset spatula on a turntable.

Tip: I preferred using a bench scraper for this cake, choose one that is at least as tall as the cake!

Step #6: Stick on the bigger sprinkles

Now that you’re happy with the look of your cake, finish the look with the bigger sprinkles. If the cake is a bit warm, put it back in the fridge before sticking on the big sprinkles.

Step #7: Paint the fault line edge

This is really an optional step, but I found that it really changes the look of the cake with the contrast of the metallic paint.

Make sure to use food safe / edible cake paint!

Sprinkle Fault Line Cake Valentine's Day

Tips to make the fault line sprinkle cake

Create a larger fault line than you would think

When you smooth the frosting, the two edges will likely come closer together!

Make sure to keep the cake cold

This was especially important when adding the sprinkles, and painting the edges of the fault line, because I used Swiss Meringue Buttercream. I imagine with American Buttercream or a crusting buttercream, this step might be less important.

Tools to create a sprinkle fault line cake

I order most of my cake making supplies from Amazon. These are the tools I used to create the look.


A cake turntable comes in really handy for this cake trend. It helps to be able to turn the cake around smoothly.

The turntable that i have and love is this one, and I got it on Amazon.

Bench Scraper

For most cakes, I find that both offset spatulas and bench scrapers work when smoothing the cake. For this cake in particular though, the bench scraper came in handy. Make sure to use a bench scraper that is at least as tall as the cake for best results!

I used this one from Ateco, and I find that the plastic handle helps with the grip, but that’s a personal preference!


As mentioned earlier, I created my own blend of sprinkles for this cake using a variety of sprinkle brands.

As part of the large sprinkles, I used the Wilton Jumbo Hearts

I used these Wilton Gold Sugar in my small sprinkle blend, among other sprinkles I got from Bulk Barn!

Edible rose gold paint

My favorite brand is this Sweet Sticks Metallic paint. I love that you don’t have to worry about mixing luster dust into alcohol or extract, which makes it an easy one step process.

I loved the contrast of pink with rose gold. Feel free to use any metallic color!

Alternatively, you can use any luster dust mixed in with some alcohol or extract as well!

Feeling inspired?

There are a lot of amazing bakers who have some extremely inspirational designs. If you’re active on Instagram, checkout the hashtag #faultlinecake!

There are no bounds to creative combinations you can come up with on this fault line trend!

And there you have it! My take on the sprinkle fault line trend. If you give it a try, let me know!

Follow me on Instagram @sprinklesandscribbles for more baking inspiration!


Sprinkle Fault Line for Valentine's Day

This Valentine's Day themed sprinkle fault line cake is made with homemade vanilla cake layers, simple vanilla buttercream, and loads of Valentine's themed sprinkles!
Prep Time30 mins
Cook Time2 hrs
Total Time5 hrs 30 mins
Servings: 8 servings


Vanilla Cake

  • 90 grams all-purpose flour
  • 100 grams granulated sugar
  • 1/4 tsp baking soda
  • 1/4 tsp salt
  • 3/4 tsp baking powder
  • 30 grams room temperature unsalted butter
  • 1/8 cups cup canola oil
  • 1 large egg
  • 45 grams sour cream
  • 1/8 cup water
  • 1 tsp vanilla extract

Vanilla buttercream

  • 180 grams egg whites about 6 large egg whites
  • 360 grams granulated sugar
  • 450 grams unsalted butter, at room temperature cubed
  • 1 tsp vanilla


  • 1/2 cup variety of sprinkles
  • 2 tbsp of water
  • Edible rose gold paint or decorative food paint


Vanilla Cake

  • Preheat oven to 350F and grease and flour three 4” cake rounds.
  • Whisk together flour, sugar, baking soda, salt, and baking powder in a bowl.
  • Add butter, and beat well with a hand mixer or in a stand mixer with the whisk attachment, until the mixture resembles fine crumbs.
  • In a separate bowl, whisk together egg, sour cream, vanilla and oil until combined.
  • Pour wet ingredients into the the flour and butter mixture, and beat on medium for 3-4 minutes. The mixture will be dry at this point.
  • Add in water and mix until just combined. Do not overmix.
  • Spread batter evenly into prepared pans. Smooth the tops with a spatula.
  • Bake for approx. 20-25 mins or until a toothpick inserted into the center comes out mostly clean.
Place cakes on wire rack to cool for 20 mins then turn out onto wire rack to cool completely before remove from pan.

Vanilla Frosting

  • Place egg whites and sugar into the bowl of a stand mixer, whisk until combined. 
Place bowl over a hot water bath on the stove and whisk constantly until the mixture is hot and no longer grainy to the touch or until it reaches a temparature of 165 degrees F on a candy thermometer. 
Place bowl on your stand mixer and whisk on medium-high until the meringue is stiff and cooled (the bowl is no longer warm to the touch (approx. 5-10mins)).
Switch to paddle attachment. Slowly add cubed butter and mix until smooth. Add vanilla and continue to whip until smooth.


  • Spread some buttercream on the cake board.
  • Place one layer of cake on a cake board and place in fridge for 5-10 minutes. This will help the cake stick to the cake board and not slip as you stack and frost.
  • Remove from fridge.
  • Top with approximately 1/3 cup of frosting and spread evenly
  • Repeat with remaining layers and apply a thin coat of frosting all over the cake for the crumb coat. Chill for 20mins.
Frost and smooth the sides.
  • Mark two vertical line on one side of the cake with a cake scraper or butter knife. This will mark the fault line.
  • Place cake in fridge for 20-30 minutes.
  • In the meantime, separate your small and large sprinkles.
  • Place approximately 2 tbsp of water in a bowl.
  • Remove cake from the fridge.
  • Dip the tips of your fingers in water before dipping them in the sprinkles. Stick small sprinkles into the fault line. Repeat until you have gone around the whole cake. Make sure to leave room for the larger sprinkles.
  • Fill a piping bag with frosting and pipe frosting above and below the fault line.
  • Scrape and Smooth with a bench scraper or offset spatula.
  • Once you’re happy with the look, place the larger sprinkles on the fault line.
  • Place cake in the fridge for another 20-30 minutes.
  • Pain the edges of the fault line with edible paint.
  • Enjoy!

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Welcome to Sprinkles and Scribbles! I'm Anum - baker, writer, accountant. Here I share the sweet side of life. Explore all things baking, books and life with me! Read More


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