Fault Line Cake Tutorial

Suuuper trendy on Instagram and Pinterest recently has been the 'fault line' cake! 

I've been seeing them literally EVERYWHERE lately, and obviously had to try my hand at a couple of my own! There are plenty of tips and tricks and tutorials all over the web right now, and I’d recommend checking for tips from a couple of people if you’re trying your first one – different people seem to have different preferences for how they create their fault lines. But in this Fault Line Cake tutorial I’ll give all the pointers that worked best for me below!

What exactly is a Fault Line cake? 

Quick throwback to middle school geography here - a fault line is a basically a crack in the earth's crust. So a 'Fault Line cake' is a cake decorated to look like a geological 'crack' runs through the center of the cake! There are a few ways to create this look, but I'll go over what I've found to be the simplest below. 

Do I need a specific cake or frosting recipe? 

Nope! I've used many types and flavors of cake layers to create fault line cakes. To decorate the outside I've used butter-based frostings and also had good results decorating with chocolate ganache! 

In the video above I used this Chocolate Cake recipe, with a caramel sauce + buttercream filling. Since I was adding ice cream cones to the top, I also added some crushed waffle cone to the filling, as well as some sprinkles for a bit of color.
I decorated with my favorite Cream Cheese Buttercream Frosting, but you can use whatever type you prefer!

How do I make a Fault Line cake? 

• (I recommend giving the video a quick watch; it outlines the process in less than a minute! Use the 'Jump to Video' button above or scroll to the recipe card.) 
• First, crumb-coat your cake – in other words, apply a thin coat of frosting to keep crumbs out of your final layer!
• Next, spread a layer of frosting around the middle third of your cake, covering the crumb coat. This is where you’ll put the sprinkles (or whatever you’d like to put in the middle of the ‘fault line’)!
  • To decorate with sprinkles, I placed a large shallow pan under the cake. (Adding sprinkles this way tends to create a mess unless there's something to catch the ones that don't stick).
• Press your sprinkles (or whatever decoration(s) you prefer) into the frosting, being sure to press any large ones in deeper so they don’t create bumps that will make smoothing your frosting difficult. 
• Now to create the ‘fault line!’ Use an offset spatula to spread a thicker frosting layer frosting around the upper third of the cake and cover the top. Take your bench scraper in several gentle swipes to smooth the frosting – be careful not to take too much off.
  • I found it the easiest to smooth the upper layer before adding the bottom layer – as suggested but @sheri.wilson on Instagram.
  • Of note here – your frosting will spread down from the top and up from the bottom as you smooth it, so don’t put it on too thick of a layer right at first! You can always go back and add more later.
• Repeat the process around the base of the cake, adding on a similar layer of frosting to the bottom third of the cake and smoothing it with your bench scraper.

Optional - if you'd like to decorate the edges of the 'fault line' a bit more!

• Mix a teaspoon of lustre dust with a 5-6 drops of vanilla extract or vodka, to create a thin paint consistency (or spray a thick layer of edible silver cake spray into a bowl or small plate).
• With your paintbrush, outline the edges of the ‘fault line’ you just created in your frosting. 

I'll include the recipe links and supplies I used to create the cake in the photos/video below. But the instructions are the important part; you can decorate your Fault Line cake however you'd like! 

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