Vanilla Buttercream Unicorn Cake

by Kate | Mar 10, 2018 | 11 comments

This isn’t just a delicious recipe for a vanilla buttercream cake, I’m going to breakdown how to create the unicorn cake that’s been flooding our social media feeds for months. Even if you’re not going to be making a unicorn cake anytime soon, below is a detailed recipe on how to bake, prep and frost a basic 6-layer vanilla cake – which, if you’ve ever been asked to make a birthday cake, should come in handy, no matter how you decide to decorate it!

First up, I just want to say that I am absolutely aware that the unicorn cake trend is basically almost over. Well, if you’re a serious baker, instagrammer or following ‘baking trends‘ that is. But if you’re a 3 year old, then a unicorn cake is still VERY much a big deal! So when I got THREE requests in one week from various family members to make a Unicorn Cake, that’s clearly the universe telling me to post it. If I’m being asked for unicorn cakes from nieces, cousins and step-daughters then obviously you are all too! So, hopefully this post will encourage you to bake any little girl (or boy!)’s dream come true…

Tip #1: Never frost and decorate a cake on the day you baked it. In other words, always prep the sponge and frosting the day or night before. Freshly baked sponges are a wonky/collapsed cake waiting to happen – especially if you’re layering them 6-sponges high!

Tip #2: Freeze (or at least refrigerate) your cake layers. Frozen cake layers are rigid and cold which makes it easier to build a straight cake and also immediately sets the frosting so it’s sturdier. Since I learnt this trick it’s changed my life!

Tip #3: Make all the fussy decorations (like the unicorn cake ears/unicorn horn) a few days before so you’ve got less to worry about.

Tip #4: Get a cake turntable. It will make your life so much easier!

Getting the look of the main on the unicorn cake usually requires a lot of different piping nozzles, but if you’re not a good piper you can buy some of these mini meringues from any supermarket and use those – I popped them on my cake in between the buttercream because I love the crunch they add! Do you regularly bake birthday cakes? I would love to hear some of your tips and what creations you’ve made – post them in the comments below!

VANILLA BUTTERCREAM UNICORN CAKE

Makes 1 large 6-layer cake (20cm wide x 20cm high) or 35-40 cupcakes

Timeline: 2 hours for baking the sponges and prepping the frosting, 3 hours for assembling and decorating

Recipe adapted from the Hummingbird Bakery Cookbook

VANILLA SPONGE

160g salted butter, softened

560g caster sugar

480g cake flour

30ml (2 tbsp) baking powder

1/2 tsp fine salt

480ml full cream milk, at room temperature

1 tsp vanilla extract

4 large eggs, at room temperature

VANILLA BUTTERCREAM

1kg icing sugar

320g salted butter, softened

100ml full cream milk, at room temperature

1 tsp vanilla extract

Pink, turquoise and purple gel food colouring

TO DECORATE

Edible glitter and gold dust

200g White Fondant

3 large wooden skewers

Quick Dry  (or you can use a little vodka)

To make the sponge, preheat the oven to 190 degrees celsius (170 if you’re using a fan-forced oven). Grease and line 6 x 20cm cake tins with baking paper. If like me, you don’t have 6 (who does), you’ll have to reline and bake the cakes in batches (which is perfectly okay).

Using an electric handheld or stand mixer (with the paddle attachment), place the butter, sugar, flour and baking powder in the bowl and mix on low speed until it resembles a sandy breadcrumb texture. Whisk together the milk, vanilla and eggs then, with the speed still on low, gradually pour the liquid into the dry ingredients. Beat the batter until smooth and light – about 2 minutes. Divide the cake batter in between your lined tins (if you’re OCD like me you can weight it so they’re all even – I used about 320g in each of my tins). Bake in the preheated oven for 20-25 minutes or until golden, springy to the touch and a skewer comes out clean. Allow the layers to cool completely before levelling them off by cutting off the tops with a bread knife. At this point I wrap the layers (usually with the base of the cake tin underneath to keep them steady) and freeze (or refrigerate) them overnight. Mix quickdry with edible gold lustre dust to form a thick paste and use a paintbrush to paint the unicorn horn, ears and eyes gold. Allow to dry.

To make the unicorn horn, ears and eyes; roll an egg-sized piece of fondant into a long sausages which tapers off at both ends (so both ends are thinner than the middle). Bring the two ends together to form a loop then twist the loop to form a unicorn horn! Insert a wooden skewer down the centre of the horn  and allow to dry overnight. For the ears, form two large triangles then round the edges off. Place the triangle in the palm of your hand to give it a curved shape and allow to dry. Pinch off two small pieces of fondant for the eyes, roll into sausages, flatten slightly and form into curves.

To make the buttercream, place the icing sugar and butter in the bowl of a stand mixer with the paddle attachment and mix until it forms a thick sandy paste. Gradually add the milk and vanilla on low speed until combined then increase to high and whip until very white and fluffy – about 5 minutes.

To assemble the unicorn cake, identify your two most perfect, level sponges – they will be your top and bottom. Place one of them on a cake board. If you’re using a cake turntable, tape the cake board to the turntable so it doesn’t move around – I use masking tape.  Top the first sponge layer with a big dollop of buttercream and use a palette knife to spread it out roughly. Top with the second sponge and press it down firmly so the buttercream underneath squishes out the sides (if you’re OCD like me, you can use a spirit level to make sure each level is straight). This is also where the cold sponges help as they’re rigid and set the buttercream almost immediately – so no wonky cakes! Continue layering sponge and buttercream, ending off with perfect sponge you reserved earlier. Using a palette knife scrape the frosting that squished out from the sides and spread that thinly all over the cake – this is called a crumb coat. Refrigerate until firm. Now cover the entire cake in a thick layer of frosting. Using a palette knife perpendicular to the turn table, scrape off an even layer of frosting to give you a smooth edge. Refrigerate again until firm.

To decorate the unicorn cake, divide the remaining buttercream into 3 bowls and tint each pink, purple and turquoise. Prepare 3 disposable piping bags with different nozzles – I used this one, this one and this one. The idea is to have large, medium and small nozzles to give varying textures. Place a different colour frosting in each. Insert the unicorn horn and ears into the top of the cake then stick the eyes on the front using buttercream. Now start piping varying sizes of swirls as the main starting at the top of the cake and working your way down the side. Sprinkle the main with edible glitter.