#TLDR A unicorn cake is a smooth white (or pastel) round cake finished with a spiralled horn, two ears, long lashes and a rainbow buttercream mane. Build a firm crumb-coated cake first, tint small batches of soft buttercream in pastels, then pipe the mane with a star tip before you add horn, ears and sprinkles. Ready-made unicorn cake decorations cut the hardest sculpting steps so you can focus on colour and piping.
Why unicorn cakes work so well for birthdays
Unicorn cakes stay popular because the look is clear from across the room: white face, gold or pearly horn, and a bright mane. You do not need advanced fondant sculpting. Most of the magic sits in clean buttercream, a few piping tips and the right toppers.
Home bakers in Australia often start with a standard 6-inch or 8-inch round stack. Two or three layers give enough height for the mane without a wobble. Vanilla or white mudcake shows pastel crumb colours if you want rainbow layers inside. Chocolate works too if you keep the exterior light.
What you need before you start
Cake base
- 2-3 baked, cooled round layers (6" or 8")
- Simple syrup or a thin jam layer (optional, for moisture)
- Cake board one size larger than the cake
- Turntable for smoother coating
Buttercream
- A batch of American buttercream or Swiss meringue buttercream, soft but pipeable
- White food colouring if your buttercream looks yellow
- Gel or oil-based pastels: pink, purple, aqua, yellow, soft blue
Decorating tools
- Offset spatula and bench scraper
- Piping bags and couplers
- Star tips such as 1M, 4B or 6B for the mane
- Small round tip for lashes or smile (optional)
Unicorn features
- Horn, ears and lashes (fondant, modelling paste, or a ready topper set)
- Edible glitter or lustre dust for the horn
- Rainbow or unicorn-blend sprinkles for the base
Shop the full unicorn collection for edible toppers, pastel colouring and themed sprinkles in one place. Pair that with food colouring, piping tips and edible sprinkles so you are not mid-project without a tip or colour.
Step 1: Bake, level and stack
Bake your layers the day before if you can. Cold cake crumbs less when you trim. Level the tops so the stack sits flat. Fill with buttercream, stack on a board, then chill 20-30 minutes so the fillings set.
If you want a surprise rainbow crumb, divide white batter into bowls and tint each with a drop of gel colour before baking. Keep colours soft. Neon batter can taste strong and muddy the crumb.
Step 2: Crumb coat, then final coat
Apply a thin crumb coat. Scrape excess so the cake silhouette stays round. Chill until firm. Add a second, thicker coat of white or very pale buttercream. Smooth with a scraper on a turntable. A clean white face makes the mane and features pop.
Yellow buttercream dulls the unicorn look. A little white colouring (oil-based options like Colour Mill White sit well in butter-heavy frostings) brightens the coat without thinning it. Keep the sides smooth; the mane covers the top and upper back, so the front face needs the most care.
Step 3: Make the horn, ears and lashes
You have three solid options:
- Ready-made topper set, horn, ears and lashes on sticks or wires. Fastest path for party timelines.
- Fondant or modelling paste, roll a tapered cone, twist gently for the spiral, dry overnight on foam. Cut teardrop ears, fold slightly, add a pink inner ear. Roll thin black or dark brown lashes.
- Edible image or printed topper, good for cupcake cakes or a flat face design.
Dry fondant pieces until they hold shape. Soft horns lean or sink. Dust the horn with gold or pearl lustre dust using a dry brush, or paint with edible metallic paint once dry. White fondant and a touch of tylose or modelling paste help ears and horns firm up.
Step 4: Tint the mane colours
Split leftover buttercream into 4-6 small bowls. Tint pastel pink, lilac, aqua, lemon and soft blue. Oil-based and gel colours keep buttercream thick. Liquid colours thin it and can make stars collapse.
For a painted-bag effect, stripe two colours inside one bag with a spatula, then fill with a third. The stars come out marbled. For cleaner blocks of colour, use separate bags per shade.
Soft pastels read more "unicorn" than neon. If a colour goes too dark, fold in untinted buttercream rather than adding white powder alone.
Step 5: Pipe the mane
Mark a soft hairline with a toothpick from forehead, over the crown, down the back. Start at the forehead with smaller stars, then build volume toward the back and down one side like a cascading mane.
Technique tips:
- Hold the bag straight up for classic stars; pull away cleanly so tips stay pointed.
- Vary tip sizes so the mane looks full, not stamped.
- Leave a clear face zone for eyes, lashes and a small smile.
- Pipe a few longer "locks" over the shoulder of the cake for movement.
A 1M tip gives big soft swirls. Open star tips (4B/6B) add texture. Practice two rows on a board first if you are new to piping. Our piping bags and tip sets make colour swaps cleaner mid-mane.
Step 6: Place features and finish
Insert the horn slightly back from centre so it does not dominate the face. Add ears either side of the horn. Press lashes above a simple black dot eye, or use pre-made lash pieces. A tiny pink nose or soft smile is optional; many cakes look sweeter with lashes alone.
Scatter unicorn or rainbow sprinkles at the base or lightly on the mane tips. Edible glitter on the horn catches party lights. Avoid heavy glitter on the whole cake if kids will handle slices.
Chill the finished cake 20 minutes so piped stars set before travel. Transport on a non-slip mat in a box taller than the horn.
Easy variations
Pull-apart cupcake unicorn, arrange cupcakes in a circle, ice as one face, pipe the mane across the top row, add a central horn. Easier serving for school parties.
Semi-naked pastel, thin white coat so crumb peeks through, then a bold mane and gold horn.
Ombre mane, pipe dark tips at the ends and lighter roots near the face.
Number or letter cake, unicorn toppers and pastel stars on a number base for age milestones.
Common problems and fixes
| Problem | Likely cause | Fix |
|---|---|---|
| Horn sinks | Buttercream too soft or horn heavy | Chill cake; use a support stick; dry fondant longer |
| Stars look blobby | Buttercream warm or over-thinned | Chill bag 5 minutes; add icing sugar sparingly |
| Face looks stained | Crumb coat too thin | Recoat after chill; use white colouring |
| Colours muddy | Overmixed gels or wet liquid colour | Tint less; use gel/oil colour; start pastel |
| Mane gaps | Uneven pressure | Pipe overlapping rows; fill holes with mini stars |
Product checklist from Baking Pleasures
Pull these when you plan the bake:
- Unicorn decorations and toppers
- Food colouring for pastels and bright white
- Piping tips and piping bags
- Edible sprinkles (unicorn blends and rainbow jimmies)
- Dusts and glitters for the horn
- Icing and fondant if you sculpt ears and horn
- Edible toppers for a faster face
Order online for Australia-wide shipping, or visit the Tweed Heads store if you want to match colours in person.
Conclusion
A strong unicorn cake is less about perfect sculpting and more about a smooth white canvas, soft pastel stars and clear features. Stack cold layers, crumb coat well, pipe a full mane with star tips, then set horn and ears last. With the right colouring, tips and unicorn toppers from Baking Pleasures, you can build a birthday centrepiece at home that photographs well and slices cleanly for the party table.