This mermaid cake with vanilla buttercream frosting is so simple to make you won’t believe it and so fun to eat you won’t be able to stop at one slice! (PS, the pearls on top are a must.)
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You guys, I have a bit of news. It’s scary stuff so prepare yourselves.
It’s almost April. As in the month that follows March. Easter is almost here! (And I hope you have a wonderful holiday if you celebrate.)
I’m excited for berry season because I have some fabulous fruity desserts planned but I’m terrified at how fast time is passing.
Good thing I have cake, right? 🙂
This mermaid cake was inspired by my love of all things colorful and sprinkle-topped. I posted these unicorn sugar cookies last year and they’re the most popular recipe on my blog.
Clearly I’m not the only one who loves sprinkles! So I decided to hop on the mermaid trend. As far as I can tell, it’s the same as the unicorn trend but with a different color scheme.
And guess what? Food that has been mermaid-ed is equally as delicious as food that has been unicorn-ified.
I know what you’re thinking. This cake, with its multiple colors, must be complicated to make. But it ISN’T! It’s super easy. It starts with a white cake mix. Then you dye one third blue, one third green, and leave the rest white. Spoon the batter into your pans about 1/4 cup at a time, layering the colors over each other. A little illustration:
Shake the pans now and then to help the batter stay even and once you’ve used all the batter gently shake the pans so the batter reaches the edges. Then bake. Then frost, then devour.
Speaking of frosting, I like to use clear vanilla when I’m going to dye my frosting because that way I get a true color. You can substitute regular vanilla extract if you want.
I used this green food coloring and this teal food coloring for my cake. I like to use gel because the color is much more vivid. This is the purple food coloring I used for the frosting.
Because I’m 99% sure all mermaids wear pearl necklaces (that just makes sense right?) the little white sugar pearls on top of the cake are a necessity. I used green and blue sprinkles too but the pearls seemed the most crucial.
OK, now that you know how crazy easy a mermaid cake can be, what the heck are you waiting for? Go bake one! It’s impossible to worry about the rapid passage of time when you have a bright purple cake staring you in the face.

- 1 15.25-ounce box white cake mix
- 1 3-ounce box vanilla or white chocolate pudding
- 1 cup sour cream
- 3/4 cup vegetable oil
- 1/2 cup whole milk
- 4 large egg whites
- blue and green gel food coloring
- 1 cup unsalted butter at room temperature
- 4 1/2 to 5 cups powdered sugar
- 2 to 5 tablespoons milk or heavy cream
- 1 tablespoon clear vanilla extract can substitute regular
- 1/4 teaspoon salt
- Purple gel food coloring
- Sprinkles
- Preheat the oven to 350 degrees. Spray 2 8-inch round cake pans with cooking spray. Line the bottoms of the pans with parchment, then spray the pans again and lightly dust with flour. Set aside.
- Combine the cake mix, pudding mix, sour cream, vegetable oil, milk, and egg whites in a large mixing bowl. Beat with an electric mixer set to medium until smooth.
- Divide the batter evenly between three mixing bowls (each bowl will have about 1 2/3 cups batter). Stir blue food coloring into one and green into another. Leave one bowl white.
- Drop a large spoonful (about 3 to 4 tablespoons) of blue batter into one of the pans. Top with a large spoonful of green, then a large spoonful of white. Continue going in that pattern until you’ve used about half of each color. Jiggle the pan now and then so the batter evens out. Repeat with the second pan. Once you’ve used all the batter, gently shake them so the batter goes all the way to the edge of the pans.
- Bake 30 to 34 minutes, until a toothpick inserted into the center of the pans comes out clean. Cool in pans for 10 minutes, then remove cakes to a wire rack to cool completely before frosting.
- Place the butter in the bowl of a stand mixer fitted with the paddle attachment and beat until very smooth. Add 4 1/2 cups of the powdered sugar, 2 tablespoons of the milk or cream, and the vanilla and salt. Mix on low until well combined then add food coloring to achieve desired color. Turn mixer to high for 3 to 4 minutes, beating until frosting is very light and fluffy. Add additional powdered sugar if frosting is too thin and additional milk or cream if it is too thick.
- If your cakes have domed, use a long serrated knife to even them out. Place one layer on a cake stand or cardboard cake circle and spread frosting in an even layer over the top. Top with second cake layer and cover cake with a thin layer of frosting. Refrigerate until frosting is set (this is your crumb coat and will prevent crumbs from getting into your final layer of frosting). Use remaining frosting to frost and decorate as desired. Serve and enjoy.





marcie@flavorthemoments says
This is SO fun Kelsie and yes — Mermaids gotta have pearls! I love all of these pretty colors!
Kelsie says
Thank you, Marcie!
Maria Doss says
Such a vibrant cake Kelsie – Pretty, fun, colorful and soooo moist. The tye-dye is such a fabulous idea, wish I lived around your neighborhood:)
Kelsie says
Thank you, Maria!
kitchenwits says
Those colors! I had no idea getting those color effects were so simple! Such a creative idea with the perfect colors for this time of year. Thank you for sharing!
Kelsie says
Thank you!
Ben|Havocinthekitchen says
I’m excited about spring and summer and all delicious fruity dishes and dessert. I also recall that last summer you kept promising to create a delightful dessert which is rather healthy and…not a cake! You are not going to let me down this summer, aren’t you?:) And this cake…I can only say WOW! Speechless.
Kelsie says
Thank you, Ben! We’ll see how a healthier dessert goes 🙂
crumbtopbaking says
Oh my gosh Kelsie! The colours in this cake are stunning! So bright and vibrant! Beautifully done my friend!! Hope you have a great Easter weekend!
Kelsie says
Thank you, Leanne! You too!
lynne hoareau says
OMW this is so fun, so gorgeous, and I love the little pearls. I so want to bake this !!! 🙂 🙂 🙂
Happy Easter Kelsie (if you celebrate) Eat lots of chocolate and lots of cake,and if you don’t celebrate Easter, still eat lots of chocolate and lots of cake. 🙂
Kelsie says
Thank you, Lynne! Happy Easter to you too!
Katherine | Love In My Oven says
Oh my goodness, this is so pretty!! Takes me right to the sea 😉 I love that vibrant purple! Oh, and I can’t wait to try those unicorn cookies!!! PS – how is it already almost April!?
Kelsie says
Thank you, Katherine! Unfortunately, YES! Time, slow down!
evolvewithmary says
I love marbled cakes like this, and of course you have now given me the confidence to think I can pull it off. My boyfriend visits your blog and sends me links all the time. LOL I know he’s going to send me this one. 🙂 Thanks for sharing such a beautiful creation.
Kelsie says
I know you could make this! You’ll have to let me know how it goes! Thank you, Mary!
Thao @ In Good Flavor says
This cake is beautiful on the outside and stunning on the inside, Kelsie! I love all the vibrant colors! Looking at it is makes me happy!
Kelsie says
Thank you, Thao!
Dawn - Girl Heart Food says
Kelsie!! The is the prettiest cake ever!!! Love all those colours and it just makes me smile looking at it! I would stare at that for, like, I dunno 2 minutes before totally digging in, lol Beautiful!
Kelsie says
Thank you, Dawn!
Marissa (@pinchandswirl) says
This is so festive and colorful, Kelsie! And I bet it tastes as amazing as it looks!
Kelsie says
Thank you, Marissa!
Kelly @ Kelly Lynns Sweets and Treats says
You definitely make it look easy!! And sooooo yummy! I love all the colors too!
Kelsie says
Girl, it is easy! Thank you, Kelly 🙂
Ashika | Gardening Foodie says
WOW Kelsie, this cake is so beautiful,I absolutely loooooove the colours, they are so outstanding and stunning. My little niece is turning 13 next week, she will adore everything about this cake including the fact that she collects every mermaid story book and pictures. I would love to surprise her with this beautiful cake.
Thank you for the beautiful recipe and have a great week 🙂
Kelsie says
Thank you, Ashika! I hope your niece loves it and has the happiest birthday!
hummingbirdthyme says
What a gorgeous cake, Kelsie! I love the color combo and that purple frosting is so stunning! I agree, pearls are a must – makes me want to watch Little Mermaid!
Kelsie says
Thank you so much, Laura! I was actually singing Little Mermaid songs as I worked on the cake, haha!
Christine says
Kelsie, What a great unique idea. I was going to order a Baskin Robbins cake for Easter but will try your mermaid cake instead.
Kelsie says
Thank you, Christine! Enjoy!
Mary Ann @ thebeachhousekitchen says
How fun is this cake?! You are so talented Kelsie! I have a niece who would absolutely love it if her aunt treated her to this cake!!
Kelsie says
Awww thank you, Mary Ann!
Milena Perrine says
Stunning! I love the purple and the color layering technique for the batter is awesome – way to impress people! I can now bake fun cupcakes for kiddos using it. Such a beautiful cake, Kelsie!
Kelsie says
Thank you, Milena!
Kim | The Baking ChocolaTess says
What a beautiful mermaid cake! I love the tye-dye and colors! My granddaughter would love this!! (not to mention, I would help her eat it!) Pinning!
Kelsie says
Thank you, Kim!
David @ Spiced says
Oh, this is a such a fun cake idea, Kelsie! Remind me again why you don’t live next door? Because I’m pretty sure if you did, I would’ve polished off this cake in about 5.3 seconds flat! Love the colors. Also, if only 99% of mermaids wear pearls, what about the other 1%? Diamonds? Rubies? Things that make you go hmmmm… Happy Monday, my friend! 🙂
Kelsie says
Hahaha! You ask some great questions, my friend. Thank you!
annie@ciaochowbambina says
Such a beauty! Almost too pretty to eat….almost! 😉
Kelsie says
Haha! Thank you, Annie!