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Mermaid-themed parties have become increasingly popular in recent years, and one of the most eye-catching elements of these celebrations is the mermaid cake. With its vibrant colors, intricate detailing, and whimsical design, a mermaid cake can truly steal the show at any event. Let me talk you step by step in creating a fun (and easy) Barbie Mermaid Cake that will leave your guests (and the birthday girl) in awe and make your party unforgettable.

Mermaid Cake feature

Over the years, as my daughter gets older she challenges me with a new birthday cake design. So far I started with rainbow cupcakes, then a monster cookie poke cake, then Peppa pig cupcakes, then a crown cake, for her 5th birthday a unicorn cake, and now onto a mermaid cake. Well, I told her one time my friend had cake with a Barbie coming out of it and she loved that idea. So then we browsed Pinterest until I combined a few ideas to come up with this mermaid cake design.

Even if you aren’t a very good cake decorator (I am by no means great) this mermaid birthday cake is do-able. I didn’t even bust out any fancy equipment to make it or decorate. Just a hand mixer, a few bowls, and spatulas. So- you got this! The smile on her face was worth every second. 🙂

Daughter with mermaid birthday cake

What you need to make this easy mermaid cake design

Cake Pans– I used a bundt pan and one cake pan because thats what I had. 2 Cake pans will work, too.

Cake Mix – Plus ingredients to make it (and I like to add pudding).

Blue & Yellow Food Coloring these two colors combined help make the teal colors in cake if using. Or just blue for the ocean color in the frosting.

Canned Frosting– You can easily make your own frosting. I like to just grab a few cans and add a little cream cheese and extra powder sugar to make it taste more homemade.

Mermaid Barbie– I Just ordered one from Amazon but I see these everywhere.

Plastic Wrap– to help keep the mermaid clean so that it can be played with afterwards.

Spatula- I like to use offset spatulas but butter knives work, too.

Graham Crackers– I crushed them up to make the “sand” on the cake.

M&M’s– I used pastel colors and could easily find them since it was before Easter but just pick out ones you want from the package or order some here.

Sprinkles or Embellishments of choice– I grabbed some edible candies from Michael’s Craft store, but something like these Seashell Icing Decorations.

How to Make a Mermaid Cake at Home

Step 1: Bake the cake. I used white cake mix and made it according to the box with some added love. I love to add an extra egg and pudding mix. Then I was trying to go for a sea-green which didn’t turn out quite the color I was going for but to do that you need blue and yellow food coloring.

I poured the batter into greased pans (like I said I used 1 bundt pan and 1 8 inch cake pan but 2 cake pans would be fine). I wanted it to be taller/ look like cascading effect so I thought the bundt pan would be helpful. Then let cool and flip out of the pans.

⭐ TIP: If you need to trim any cake to help them lay flat, just use a serrated knife.

Step 2: Make the Frosting. Same thing here I just grabbed a few cans of white frosting (always grab extra to make sure you have enough). I like to add a little cream cheese for some homemade taste. Then a few drops of blue food coloring to get the ocean color you like.

how to make mermaid cake

Step 3: Prepare the Mermaid Barbie. This one came with a tail that I had to pop off. Then I wrapped her tail up in plastic wrap so it wouldn’t get cake/frosting on it. I also tied her hair with a few rubber bands so that it wouldn’t lay in the frosting.

Step 4: Assemble Cake. If you are using two cake pans, just cut a little circle in the middle of each (reserve the cake you removed). The bundt pan obviously already is good. Place one cake on a plate or platter. Frost the top and then add the other half of the cake. Slowly and carefully add the mermaid into both holes.Crumble the reserved cake into the hole and around the barbie to help hold her in place.

Step 5: Frost the Cake. Go ahead and frost the cake on the sides and on the top. And up the mermaid body just a bit.

Step 6: Decorate. I crushed graham crackers in my food processor to make “sand”. Add some graham crackers around the mermaid to make it look like she is sitting on the sand. Then I added it around the base of the cake, too.

how to make mermaid tail on cake

For the mermaid tail, I picked out the color M&.M’s I wanted to use and alternated them with them slightly sticking up to look like scales. Continue down, get a little slimmer, then go back out to make the fin. Then a I added a few embellishments with edible starfish, seashells, etc. I also use mermaid colored sprinkles from the Dollar Tree.

Mermaid cake with embellishments

If you are adding cream cheese to your frosting, make space in your fridge and refrigerate until party time. I had a cake box that I left open and added plastic wrap around it so it wouldn’t get dried out. Then After you sing, slice and serve! Enjoy 🙂

Mermaid Birthday Party Ideas

Mermaid birthday party ideas

Of course I had lots of fun on Pinterest finding some ideas other festive mermaid themed birthday ideas. For the party and decorations, I used & bought:

  • Ocean Water Punch” from We’re the Joneses
  • Clam Shell Cookies from MomDot
  • Mermaid & Shark Fruit Snacks (purchased from the Dollar Tree)
  • Vanilla Cupcake Flavored Goldfish
  • I also made Mermaid Chocolate Tails with candy melts in these little silicone molds.
  • Mermaid Tail balloons from the Dollar Tree. The Jelly fish were borrowed from a friend but she got them from Party City.
  • The mermaid plates and napkins were at the Dollar Tree as well!
Girls at mermaid birthday party

Like this Birthday Cake Design? Check out my:

Make sure to PIN IT!

Mermaid Barbie cake pin

How to Make a Fun Barbie Mermaid Cake

Make an easy Barbie Mermaid Cake at home for your next mermaid birthday party!
Prep Time10 minutes
Active Time1 hour
Course: Dessert
Keyword: barbie, birthday cake, birthday party, mermaid, mermaid cake design
Yield: 1 cake

Equipment

  • 1 Hand Mixer

Materials

  • 2 Cake Pans
  • 1 box White Cake Mix (plus ingredients to make) see notes
  • 2-3 Cans of frosting see notes
  • 1 Mermaid Barbie Doll
  • Plastic Wrap
  • Blue & Yellow Food Coloring
  • Offset Spatula or regular
  • Pastel M&M's
  • Graham Crackers
  • Edible Embellishments/ Sprinkles optional

Instructions

  • I used white cake mix and made it according to the box. I love to add an extra egg and pudding mix. Then I was trying to go for a sea-green which didn't turn out quite the color I was going for but to do that you need blue and yellow food coloring.
  • I poured the batter into greased pans (like I said I used 1 bundt pan and 1 8 inch cake pan but 2 cake pans would be fine). I wanted it to be taller/ look like cascading effect so I thought the bundt pan would be helpful. Then let cool and flip out of the pans.
    ⭐ TIP: If you need to trim any cake to help them lay flat, just use a serrated knife.
  • For the frosting I just used cans of white frosting (always grab extra to make sure you have enough). I like to add a little cream cheese for some homemade taste. Then a few drops of blue food coloring to get the ocean color you like.
  • If you are using two cake pans, just cut a little circle in the middle of each (reserve the cake you removed). The bundt pan obviously already is good. Place one cake on a plate or platter. Frost the top and then add the other half of the cake. Slowly and carefully add the mermaid into both holes.Crumble the reserved cake into the hole and around the barbie to help hold her in place.
  • Next frost the cake on the sides and on the top. And up the mermaid body just a bit.
  • I crushed graham crackers in my food processor to make "sand". Add some graham crackers around the mermaid to make it look like she is sitting on the sand. Then I added it around the base of the cake, too.
  • For the mermaid tail, I picked out the color M&.M's I wanted to use and alternated them with them slightly sticking up to look like scales. Continue down, get a little slimmer, then go back out to make the fin.
  • Then a I added a few embellishments with edible starfish, seashells, etc. I also use mermaid colored sprinkles.
How to make a mermaid cake Pinterest