I made this Ariel the Little Mermaid cake for little Hashreyaa on her 3^rd birthday. This cake is one of the many cakes I have made for this little girl and her brother, Arya. Hashreyaa’s mom is a special customer of mine who happens to be my sister’s close friend and I have always enjoyed decorating cakes for her as she truly appreciates the taste of my cakes and my decorating.

This 3rd-year birthday celebration was a little special as the girl had 2 cakes. This Little Mermaid cake was one of them, while the other one was a “Jake and the Never Land Pirates’ themed cake. I have written all about Jake and the Never Land Pirates cake on a separate page and you can read all about it there.

A square blue cake decorated with Ariel the Little Mermaid characters. — Ariel Little Mermaid Cake Design - A Mermaid Themed Birthday Cake

Easy Little Mermaid Buttercream Cake

Back to this cake. This is a buttercream cake. Well, butter icing to be precise. What’s the difference you ask? Well, buttercream is buttercream, and butter icing is the stiffer version of the buttercream which means it has more icing sugar in it, thus making it stiffer. These are my own terms to describe my two different versions of the butter-based icings. You can get the buttercream recipe here and the butter icing recipe .

Generally, between the two, I prefer to use butter icing as I find it easier to achieve a smooth surface on cakes. I am just not a skilled buttercream person so achieving a smooth surface on cakes is not quite my forte.

Anyway, back again to the homemade Disney Little Mermaid cake. Overall, this was a pretty easy cake to decorate. All the figurine toppers on the cake were toy toppers and the rest of the decoration on the cake was in fondant.

Let’s look at my decorating tutorial for this Ariel Little Mermaid DIY cake below.

How to Make the Little Mermaid Cake

Main supplies for the mermaid themed cake:

Cake – this was a 9 inches square cake baked using my pound cake recipe. I baked the cake in 2 layers and once stacked, the overall height was approximately 4 inches.
Buttercream – I used this icing to fill and crumb coat the cake. Get the buttercream recipe here.
Butter icing – this is the stiffer version of the buttercream. Click here for the butter icing recipe.
Fondant – I used Satin Ice for all the sea themed decorations on the cake (except for the figurines).
Ariel the Little Mermaid themed toy toppers
Pizza cutting wheel – I used this as a general cutting tool for the deco on the cake.
Sea waves cutter – This was sea wave-shaped, and I purchased it from Not Just Cakes by Annie.
Fondant shaping tools
Round plunger cutter set– these were for the holes on the brown sea sponge on the cake.
AmeriColor White gel food coloring & fine tipped cake decorating brush
Wilton gel food colors in royal blue, pink, juniper green, violet, brown, yellow.
Hot glue – I used hot glue to hold the figurines on the cake board securely in place.
Block letters alphabet cutters
Needle scribe tool – this was to mark the lines on the seagrass.
Small daisy flower cutter – I used this for the brown starfishes on the cake.

The Little Mermaid cake toppers

The toy toppers on the cake were provided by my customer. She handed them to me a few days in advance and that gave me sufficient time to plan and estimate the placement of the Disney themed figurines on the birthday cake and the cake board.

Preparing the birthday cake

And so, closer to the cake delivery date, I baked the cake. This was a 2 layer cake sandwiched with buttercream.
Once the cake layers were baked and have cooled completely, I leveled the tops and filled filled buttercream. And then I crumb coated it with a thin layer of buttercream. The crumb coat was to make sure the top and sides of the cake were all level and flat.

Buttercream sea effect on the cake

Next, I covered the cake with butter icing. I tinted it with Wilton Royal Blue food color. Since the icing has a natural yellow hue to it, adding blue to it turned it into a blue with a slight hint of green. That sea blue color was very fitting for this cake. It was meant to represent the seawater.
I applied the icing all over the cake and then, instead of smoothing it flat, I pressed it down with my fingers. The dents were meant to represent sea waves.

Once the entire cake was covered in butter icing sea waves, I made the border. I used blue fondant for the border and used my sea waves cutter to make a layer of waves and attached them all around the base of the cake.
The butter icing was able to hold the fondant strips in place without the need for any additional fondant glue.

The lettering on the cake

After that, I added the wordings on the cake. The letters were made using my block letter cutters. I purchased these from a local cake decorating supplies shop. I used pink tinted fondant for the letters.
Once the letters were in place, I made the rest of the decoration for the Little Mermaid theme. I started by adding the long sea grass on the corners of the cake. The grass was cut using my pizza cutting wheel and the lines on the grass was made using my sugar craft needle scriber tool.

Green fondant grass on a blue cake. — DIY edible grass decoration on the sides of the Little Mermaid Cake

The pink corals edible decorations

Next were the pink fondant corals. These were shaped by hand and I used a thin wooden skewer to poke holes all over the coral. And then I attached it to the sides of the cake. I did not need any special glue to stick the deco to the cake, the butter icing was able to hold the decoration well in place.

Pink fondant corals on a blue cake. — Fondant Corals - Edible decorations on the Little Mermaid Cake

Edible sea creatures in fondant

For the brown and yellow sponge, I rolled some brown and yellow fondant thin, and used my round plunger cutters to make random holes in random order all over the rolled pieces. And this went on the sides of the cake (brown sponge) as well as the top (yellow sponge) of the Little Mermaid cake.

Next was the cluster of purple cylinder-shaped sea plants. I made these individually by rolling some purple fondant into sausages. Using the pointed end of my shaping tool ( the one that is shaped like a pencil), I made holes on one end of the sausages. I then grouped a few of them together and attached them to the cake.
When grouping these together, I dampened them slightly with a damp brush so that they would stick to one another. And in attaching the clusters to the cake, again, the icing was sufficient to hold them in place. I made a few clusters of these and added them to the sides of the cake.

DIY fondant fish

After all the edible sugar sea plants were done, I made the yellow fishes for the front side of the cake. These were formed by hand using yellow fondant and the shapes were then enhanced with the help of my shaping tools and sugarcraft knife. I then added light blue strips and black eyes for the fishes.

Yellow fondant fish on buttercream cake. — Hand Shaped Fondant Fishes on the One Layer Little Mermaid Cake

The fondant starfishes

The next decoration to go on the mermaid themed cake were the brown starfishes. I cut these with my small daisy flower cutter and added white polka dots using a fine-tipped cake decorating brush and white food color. The white paint was undiluted white gel food coloring. These starfishes were randomly placed on the sides and top of the butter icing covered cake.

Sea creatures in fondant, on a blue cake. — Under the Sea Cake Decorations in Fondant

Once all the cake decoration was done, I arranged the Disney themed toy toppers on the cake. For the figurines on the cake board, I used hot glue to hold them in place. The ones of the cake were simply placed on the cake and since they had wide bottom bases, they were able to stand on the cake well.
I added more decoration on the sides of the Little Mermaid themed figurines on the cake just so that everything looked as naturally placed as possible.

And that’s that. My Ariel Little Mermaid cake design.

Like this easy Little Mermaid cake idea? Here are my other posts you might want to check out:

Recipe (Printable)

Here is the full printable version of my Ariel Little Mermaid cake recipe and decorating tutorial.

📖Recipe

Happy Decorating 🙂

Ariel Little Mermaid Cake Design - How to Make

Easy Little Mermaid Buttercream Cake

How to Make the Little Mermaid Cake