How To Make Classic Primary School Sprinkle Cake

29 Apr 2020

I think people within a certain age bracket will remember this very clearly. You're standing in the queue in your primary school, waiting to get your dinner. You pick things from the random options in front of you (pizza and mash, anyone?), slowly shuffling down to the pudding end of the line, crossing your fingers and hoping for the sight of rainbow sprinkles. And when you spot them, you know that you're in for the best pud possible! Yes, I've been missing school days a lot recently and so I had to bake something that made me feel all those nostalgic fuzzies inside - classic primary school sprinkle cake.

I realise that not everyone is fully aware of the taste sensation that is primary school cake, so to explain, this cake is simply a vanilla sponge traybake that's topped off with glace icing and rainbow sprinkles. Seriously, that's all it is, yet somehow, it managed to capture the hearts of every single kid in the school dinner queue. I can't explain why it was so good, you'll just have to trust me (and the boat load of people who voted that I bake this treat on Twitter and Instagram - thanks guys!).

Now obviously, you guys know me - I like to mix things up a bit and experiment a little bit with recipes to make them that extra bit more amazing. As I mentioned, these slices of joy are usually topped with glace icing, but in my opinion, glace doesn't look the best and I didn't want it to separate or soak into my cake overnight. Instead, I mixed a bit of Sugar & Crumbs' Velvet Vanilla icing sugar with plain icing sugar, milk and a teensy bit of butter. This made the mixture a bit thicker and like a thin buttercream. It spread over the top very easily and set to hold its shape, whilst still letting you cut through with total ease.
While the icing is absolutely jaw-droppingly delicious, it's definitely all about the sponge with this traybake. It's super duper light and bouncy, and has that signature yellow tint to it that all of us who have tried this cake know and love. That comes from the 5 eggs that get mixed in... I know, 5 eggs seems excessive, but trust me, you'll get that gorgeous golden colour and beating them in will add tons of air to make the mixture gorgeously light. You also want to make sure that your butter is nicely softened and at room temperature to make the creaming easier and give you a smoother texture.

Of course, there's no other way to top this traybake off than with lashings of rainbow sprinkles or hundreds and thousands. This is the way that the cake was served up and when hot custard was poured on top, the colours would run and swirl together into a masterpiece of a pudding. But if you're not a fan of the humble rainbow sprinkle, it wouldn't hurt to top this cake off any way that you like - chocolate shavings, silver dragees, a spritz of shimmer spray or even just leaving it plain. Whatever floats your boat!

This recipe was designed to make a lot of slices and I recommend using a 30cm x 23cm tin. You could probably cut it to about 20 slices, but in our house, we go big, so we managed to get about 14 chunky squares out of it. If you want to use a smaller tin, you can always half the recipe or bake in batches. It's also worth mentioning that this cake will freeze, so if you want to save some slices for a later date, pop them in the freezer and defrost when you're in the mood!

For the sponge, you will need:
300g unsalted butter, softened
150g caster sugar
300g self raising flour
5 large eggs
95ml milk
1 teaspoon vanilla essence

For the topping, you will need:
50g unsalted butter, softened
50g Sugar & Crumbs Velvet Vanilla Icing Sugar
300g plain icing sugar
4 tablespoons milk
Rainbow sprinkles

  1. Preheat your oven to 160c/140c fan/gas mark 3, then grease and line a 30cm x 23cm baking tin with greaseproof paper.
  2. In a large bowl, cream together the butter and both of the sugars until they become light and fluffy.
  3. Add the eggs into the bowl one by one, beating the mixture between each one until fully incorporated.
  4. Add the flour into the mixture two tablespoons at a time, beating after each addition so that the mixture becomes smooth and thick.
  5. Pour in the milk and vanilla essence, then mix well until everything is combined. Take care not to overmix though!
  6. Pour your cake mixture out into the prepared tin, then bake in the oven for around 25-30 minutes. The cake should be golden brown and have a lovely level top.
  7. Once your cake has baked, remove it from the oven and allow it to cool in the tin for around 15 minutes, then turn it out on to a wire rack to cool fully.
  8. While your cake is cooling, prepare the icing. Beat the butter in a large bowl to soften it further. Gradually beat in the icing sugars and add the milk, beating after each tablespoon. The mixture should become smooth and have a thin buttercream texture.
  9. Once your cake has fully cooled, dollop your icing on top and spread it out with the back of a spoon. Add your rainbow sprinkles on top, then let the icing set before slicing the cake into squares.
Like I said, this is a pretty simple sponge cake, topped off with vanilla icing and sprinkles - nothing more, nothing less - yet something about it is just so delicious and brings on so much nostalgia. But maybe it's the simplicity of it that is so yummy? While we all love a cake with bells and whistles, something simplistic like this with classic flavours and a basic look just never goes out of fashion. 

This is the perfect traybake to whip up to go alongside a hot drink or to give your kids a glimpse into the good old days of school dinners. You could even make your own pink custard to serve it up with! Now that would be a blast from the past.

What was your favourite thing about primary school?

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