Rainbow layer cake recipe

This rainbow layer cake looks utterly professional but is very easy to create at home. 

Rainbow layer cakes definitely give off the vibe of being better left to professionals, but this is impressively easy to create. You will need five cake tins to create it (unless you want to do it in batches so you can reuse the same tins). The layers are separated with a thin smothering of lemon curd, which gives just the right moistness and lemony tang to the sponge. On the outside is a classic cream cheese buttercream icing and of course, plenty of rainbow sprinkles. This cake serves up to 15 people and it's an absolute crowd-pleaser.

Ingredients

• 5 large eggs
• 300g margarine
• 300g golden caster sugar
• 300g self-raising flour
• Finely grated zest of 1 lemon
• 2 tbsp lemon juice
• Red, pink, yellow and blue paste colour

For the filling and frosting:

• 5-6 tbsp lemon curd
• 150g unsalted butter
• 300g icing sugar
• 125g full-fat cream cheese
• 100g sugar sprinkles

Method

1. Grease and base line 5 x 15cm cake tins. If you don't have five you can cook the layers separately but it's best to wash the tins between each use to prevent mixture sticking or colours bleeding into each other. Heat the oven to 180°C. Put the butter, sugar, eggs and flour in the bowl of a free-standing mixer (or use an electric hand whisk if you don't have one) with the lemon zest and juice. Mix together until smooth.
2. Take five bowls and evenly divide the mixture between them. Add a dot of red paste colour to one, pink to another, yellow to another and two dots of yellow colour with a dot of red paste for the orange layer, and a dot of blue to another. Stir each one to evenly mix in the colour. Pour the mixtures into a separate tin each.
3. Bake for 15 minutes or until a skewer inserted in the centre comes out clean. Upturn the cakes, remove from tins, cool on a wire rack.
4. Whizz the butter and icing sugar together in a processor or mixer until smooth and well combined, add the cream cheese and pulse for just a few seconds to mix in.
5. Place a little bit of lemon curd onto a cake stand or plate and put the green cake on top to make sure it doesn’t move, spread over 1 tbsp lemon curd. Layer up the coloured cakes with lemon curd in between.
6. Spread a thin layer of frosting over the sides of the cake and chill for 10 minutes. Spread a thicker layer around the cake sides. Tip the sprinkles down the centre of some baking parchment. Lift the cake, holding it by the top and base, then roll the sides in the sprinkles to cover. Put on a serving plate.
7. Spread rest of the frosting on top of the cake. Finish by pushing in a cake topper.

Top tip for making this rainbow layer cake

If you're not a fan of lemon curd you can use apricot jam between the tiers instead, or make extra frosting and add a thin layer of that between.

How can I make this cake without buying five cake tins?

Because the sponge only take 15 minutes to bake, it's actually quite easy to make this cake in batches. We'd recommend having at least three identical cake tins, so you can cook in a maximum of two batches. This is because you make all of the cake batter at the same time, and you don't want it to hang around unbaked for too long. Ensure you cover the waiting batter while you cook the first batches. 

Allow an extra 10 minutes per cooked batch for the sponges to cool down slightly in the tin before you turn them out. Keep an extra close eye on later batches while they bake as the oven temperature may fluctuate over time. 

Is liquid or gel food colouring better for this rainbow layer cake?

Gel food colouring is much more concentrated than traditional liquid food colour. You will get a better, brighter colour from only a couple of drops of gel food colour, than from a teaspoon of liquid. This is good for the sponge as well because it means you are adding less liquid to the cake mix.

You might also like...

• Rainbow cake
• Rainbow cupcakes
• Rainbow cake pops