Cover a cake with an all-over shell design! This Purple Shell Cake is simply one motion repeated over the entire cake. So simple. So pretty!

Simple, fast, and so easy to personalize!
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I had some purple frosting left over from my Purple Ombre Messy Ruffle Cake so decided to try something different. A “clean” ruffle! This cake is basically the same as the messy ruffle only a bit more precise and organized. (I originally shared this design in 2013 on my Perfect White Cake, just in case you want to see it in a different color)

To make this cake you will need:

white cake recipe (I used a box mix for this cake, it was 4 cups of batter so I put 1 1/3 cup batter into each  cake pan)

8-inch round cake pans

buttercream recipe

food color for buttercream (I used the formula for “pretty purple” and “deep purple”)

extra confectioners’ sugar (if your frosting gets too creamy)

pastry bags (I double bag all my frosting and you can see that here)

#21 tip (can also use a #18)

Purple Shell Cake

I had to use SO much food color to achieve the deep, rich purple that I changed the integrity of my frosting. It was so soft and creamy that it did not want to hold that messy ruffle, so I had to go back and add a bit more confectioners sugar. This helped the frosting to not droop as much.

I added “extra confectioners sugar” above as a reminder for you. If after you have achieved your desired color the frosting is too creamy, feel free to add some more sugar to stiffen it up. I would start with 1/4 cup at a time.

You can also chill the frosting for 5 minutes in the freezer.

PRO TIP: Frosting will DARKEN over time.

Add your food color until you are close to the color you are trying to match but not quite there… then let it sit for 10 minutes. You will see that the color has deepened!

Tools for Cake Decorating

(In the video below I show how I created the lines around my cake in case you are a visual person)

To get somewhat even lines around my cake I used this handy dandy scraper. I use this ALL THE TIME and for so many things, but mainly for creating a smooth, clean edge of the cake. It happens to have a ruler on the side so I held it up to the side of my cake and created a mark every inch with the toothpick.

I then went back and make a line on the side of the cake with the scraper itself.

I also drew a line around the center of the cake with the toothpick (just freehand).

The round (kinda) cookie cutter was used to create a guideline on the top of my cake where I added some of the dark purple frosting.

Decorating Tips

I just want to show you the #21 tip. These are all the same tip shown just how they arrived. As you can see, there are some big differences! Some a closed, some open, some bent. This WILL produce different looks, so what should you do?

I recommend trying to bend the tines in with the back of a spoon for a more closed look. If you want the stars to be more open (like on the 3rd tip) you can put the end of a wooden spoon up into the tip and gently press out.

I chose the 2nd tip, or the slightly closed tip, to make this cake.

(FYI: You can see more of my decorator’s tips here.)

Here is a video on how to made this cake: (this one is long but I have a 15-second version on Instagram!)

As you can see this cake goes quickly, is easy to master, and is quite pretty to look at! (If I am allowed to say that about my own cake!)

Simple, fast, and so easy to personalize!

I couldn’t stop taking pictures of it… the way the light hit those little groves of frosting was mesmerizing.

Actually, just decorating this cake was an experience in relaxation. 🙂

If you like this cake be sure to check out my other decorated cakes here!

Simple, fast, and so easy to personalize!

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Meet Amanda Rettke

Amanda Rettke is the creator of I Am Baker, and the bestselling author of Surprise Inside Cakes: Amazing Cakes for Every Occasion – With a Little Something Extra Inside.Over the course of her 15+ year blogging adventure, she has been featured in and collaborated with the Food Network, New York Times, LA Times, Country Living Magazine, People Magazine, Epicurious, Brides, Romantic Homes, life:beautiful, Publishers Weekly, The Daily Mail, Star Tribune, The Globe and Mail, DailyCandy, YumSugar, The Knot, The Kitchn, and Parade, to name a few.

Reader Comments

  1. Happy fifteenth years blogging anniversary deliciousness🎂🍰
    Happy to be your follower for just less than two years
    All my my life I don’t realy bake since the day I follow you on fb thts the time I try to bake
    I learned baking through you with a Bunos of your techniques
    I have try your lemon bars sugar cookies red velvet cake me mny more they re worth it to give a try
    In your web page there’s never ending learning in baking cause I try to make your cake decorating recipes
    Hope I could grab one of your cakes book at stores
    More power and God blessed you iambker

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