Union Jack Sponge Cake


This Union Jack Sponge Cake is one of the simplest recipes I have made and yet it is also one of the most delicious cakes I’ve ever made.

FF Union Jack Sponge Cake
Union Jack Sponge Cake

A light vanilla sponge base, covered and piped with freshly whipped cream and decorated with strawberries and blueberries. Finally, a sprinkle of caster sugar and glitter sets this cake off.

So, why bake a flag cake?

On Twitter there is a community run by two fabulous, fun women, called @SundayBakeClub, they were recently featured in the Telegraph newspaper. And each week they pick a different theme that challenges bakers to express their creativity, try news skills and most of all, have fun! Last Sunday’s theme was #GirlPower. So, the Spice Girls and our longest reigning monarch, Queen Elizabeth II, were my inspiration.

Resulting in this Union Jack Sponge Cake.

FF Union Jack Sponge Cake
Union Jack Sponge Cake with pretty piped cream edges.

Adapting The Bake To My Circumstances

To be completely honest my original idea was to make a cheesecake with a Union Jack design on it, however, I woke up on Sunday with a cracking migraine. As a result, I resigned myself initially to not being able to take part. Yet, later in the day the pain eased enough for me to get a sponge base made and baked. And then back came the pain. So I went back to bed!

After a couple of hours I was able to get up and decorate the cake. And I am really pleased that I saw this bake through. However, you have no idea how many times I start a recipe, only for me to be too unwell to complete, or photograph the results. So, on this occasion #GirlPower really did prevail.

FF Union Jack Sponge Cake
Union Jack Flag Cake my lunch portion the following day!

Sunday Bake Club – a community of bakers

I adore how the Sunday Bake Club is a community of bakers who inspire and help each other. Although, the main focus is to encourage people to get baking and stretch those who already bake often. Most importantly, the community engage in a completely non competitive and supportive way. While ‘Best Bits’ are chosen, by the organisers each week and posted on to their Blog, bakers can then vote for their favourite bake and a ‘winner’ is awarded a virtual golden spoon, just for fun!

A few weeks ago I was very fortunate to be awarded a golden spoon for my Hazelnut Raspberry Vacherin, I promise to write it up and post it on here soon. It has three tiers of hazelnut meringue with whipped cream, raspberries and toasted hazelnuts in between and on top. While it was a real technical challenge for me the finished bake was worth my effort!

Back to the Union Jack Sponge Cake, you will need a 20cm x 28cm x 5cm (8″ x 11″ x 2″) Swiss roll tin to bake this flag cake.

Recipe: Union Jack Flag Cake serves 12

For the cake:

225g/8oz Unsalted Butter at room temperature – plus an extra tablespoon for greasing the tin

225g/8oz Caster Sugar

1/4tsp Salt – I use Maldon

2tsp Vanilla Bean Paste – I use Nielsen-Massey

4 Large Free Range Eggs

225g/8oz Plain White Flour – plus an extra tablespoon for dusting the tin, alternatively use self raising flour and leave out the baking powder.

2tsp Baking Powder

To decorate the cake:

400ml Double Cream

300g Fresh Blueberries

400g Fresh Strawberries

1tsp Caster Sugar

Optional – edible glitter or caster sugar

Preheat the oven to 160C/140C fan, gas mark 3, 325F.

Making The Sponge Cake

  • First of all, thoroughly grease the Swiss roll tin using the extra 1 tablespoon of butter.
  • Next add one tablespoon of flour and tip it around the tin until the inside of the tin is completely coated. Tip any excess away into the bin.
  • In a large bowl add the butter, sugar and salt.
  • Whisk or beat together until pale and creamy.
  • Add 1 teaspoon of vanilla bean paste, all four eggs and the flour.
  • Whisk or beat slowly until everything is just combined. Finish mixing using a spatula or spoon to ensure all the ingredients are combined, taking care not to over mix as this can result in a heavy cake.
  • Tip the cake batter into the prepared tin and smooth out so that it fills each corner and is even.
FF Union Jack Sponge Cake
Delicious light vanilla cake batter ready for the oven.

Baking The Sponge Cake

  • Place in the centre of the oven and bake for 30-40 minutes.
  • The sponge is baked when it is golden and springs back from a light touch.
  • As soon as the cake is baked, remove the tin from the oven and allow the cake to cool for 10 minutes in the tin.
FF Union Jack Sponge Cake
Beautifully golden baked sponge.
  • Run a palette knife around the edge of the cake and then tip the sponge out on to a cooling rack.
  • Allow the sponge to cool completely before decorating.
  • Since I don’t have a board large enough for this cake, I placed it on to some baking parchment and then back on to the cooling rack to decorate.

Decorating the Union Jack Sponge Cake

  • Place the cold fresh cream, 1tsp of caster sugar and 1tsp of vanilla bean paste into a bowl.
  • Whisk until the cream just holds a stiff peak.
  • Place half of the whipped cream into a piping bag fitted with a large star tip. Secure the bag and place in the fridge. It was an extremely hot summer’s day when I made this cake, so I had to work quickly.
  • Spread the other half of the whipped cream on to the surface of the cake, using a palette knife to achieve a flat even finish. You DO NOT need to cover the sides in cream.
  • Hull and slice the strawberries. Wash and dry the blueberries, sorting through them as you dry them to remove any stalks or over ripe berries.
  • Have a picture of the Union Jack flag in front of you. While you can use my cake as a reference, a picture is more accurate.
  • Start by forming the central red cross using sliced strawberries.
  • Cut some of the strawberry slices in half. Angle these into the cream to create the X shaped cross.
FF Union Jack Sponge Cake
The Union Jack Sponge Cake is starting to take shape.
  • Use blueberries to fill in the triangles ensuring there is a gap of plain cream to represent the white lines of the flag.
  • Now pipe stars around the outside. I first piped around the bottom edge of the cake and then again around the top edge. It gives the cake a beautiful finish.
  • If, like me you like a few sparkles, sprinkle over some edible glitter or caster sugar to complete your Union Jack Sponge Cake.
FF Union Jack Sponge Cake
Union Jack Sponge Cake perfectly pretty and very tasty.

Chilling And Serving The Cake

I popped the whole cake, uncovered, into the bottom of the fridge for an hour before serving. It helps the cream set and cools the cake down. As I mentioned I baked and decorated this cake on a very, very hot day.

If the temperature isn’t melting everything in sight this Union Jack Sponge Cake is fine to serve as soon as it has been decorated. Cut into squares, or slice down the centre and serve as slices.

This cake keeps exceptionally well, in an airtight tin for 5 days in the fridge. It remained light and fresh and is simply one of the best cakes to enjoy with a cup of tea!

If you have enjoyed this Union Jack Sponge Cake recipe, here are some others you may like:

Raspberry Almond Cream Cake

FF Union Jack Sponge Cake
Raspberry Almond Cream Cake simply delicious.

Loveliest Lemon Curd Cake

FF Union Jack Sponge Cake
Lemon Curd Cake so tangy and refreshing.

Black Forest Giant Doughnut

FF Union Jack Sponge Cake
Black Forest Giant Doughnut with a hint of kirsch.

The baking community on Twitter are very encouraging and supportive, as well as a constant source of inspiration for me. Everyone shares and seeing as how I’m that kind of person, I fit in well!

Whatever time of year you make this cake, use whatever seasonal berries are available. I bet it would taste wonderful with raspberries and blackberries!

Thank you for all of your comments both here, on Twitter and Instagram. Hearing and seeing your creative, culinary makes is a constant source of encouragement and inspiration to me.

So, whatever you are making, baking and creating in your kitchens, have fun preparing and sharing your feast.

Sammie xx

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Note: Since this year, 2020, is the 75th anniversary of V.E. Day, this cake is an easy and beautiful way to bake and celebrate with those you live with, during this unusual time of Covid-19 lockdown. Why not get creative and create the flag decoration with whatever berries, dried fruit and sprinkles you have in your kitchens? Most of all, stay safe and well during this challenging time. X


Fresh berry decorated flag bake dessert.