How to Decorate a Whimsical Mermaid Cake

Looking for inspiration to create a whimsical birthday cake that’s both playful and elegant? This dreamy mermaid cake design blends soft pastels, vintage charm and seaside magic – perfect for a Little Mermaid party, an Under the Sea birthday cake, or any celebration that needs a touch of fantasy.

Best of all? You can watch the full decorating process in our video tutorial – perfect for picking up tips, seeing the moulds in action, and following along step-by-step.

The Star of the Show: Mermaid Silicone Mould
At the heart of this cake is our Mermaid Silicone Mould, which creates a detailed mermaid figure ideal as a centrepiece. Made in the UK from high-quality, food-safe silicone, the mould is easy to use with fondant, modelling chocolate or sugarpaste.

Adding Vintage Flair to the Fantasy
Our Large Oval Vintage Frame Silicone Mould adds instant 1950s glamour, framing the mermaid in aqua blue. Its ornate detail complements the ocean theme while introducing a classic feel.

Ocean Elements in Soft Pastels
To build the underwater look, we used our Seashells Silicone Mould and dusted the shells in soft pearlescent pinks. The S Scrolls Silicone Mould created elegant details that echo the movement of water and waves.

Floral Finishing Touches
Add delicate florals using our Flower Pro Filler Flowers Silicone Mould and Fabric Flowers & Fancy Leaves Silicone Mould in colours to match your scheme. We also used the Flower Pro Fan Veiner to create a shell texture and The Measuring Mould to make bubbling accents.

A Modern Cake with Vintage Flair
The result is a cake that’s beautiful, modern and just a little bit kitsch – in the best possible way. With its soft pastel tones and nostalgic details, this cake works equally well for children’s parties and adult celebrations. Every mould used in this design is proudly made in the UK using food-safe silicone, trusted by professionals and hobby bakers alike.

🎥 Watch the video now and see how easy it is to bring this magical cake to life.

Decorate a Mermaid Cake

All the moulds you'll need

Brush the Mermaid Silicone Mould with cornflour then press firm fondant (such as Renshaw Extra) into the mould. Flex the mould to release with ease. Colour with edible gel paints and brush with pearlescent lustre (such as Rainbow Dust). Once dry, attach to your cake with edible glue.

More Mermaid Inspiration

More Sea Themed Moulds