Sponge Cake with Strawberry Mousse [Birthday Cake]



Sponge with Strawberries – a Summer Classic


I don’t know about you, but a sponge with whipped cream and strawberries is a summer classic for me. For as long as I can remember my grandmother used to make it at least 5 times in a season.

I have also made it loads of times. Often without any special occasion, just to celebrate the plentiful of strawberries.

This time, however, I wanted to add a twist to it.


Sponge with Strawberry Mousse – a Summer Classic with a Twist

So, instead of adding pieces of strawberries to the whipped cream, I mixed everything together to make a strawberry mousse.

The idea was superb: the mousse was delicious. The only issue was that it wouldn’t be stiff enough, so I had to add gelatin. But obviously, that was not a big problem.

While I was making this strawberry , I also wanted to try out a new decoration idea. I had seen it somewhere some time ago and was very impressed by its look.


Sponge with Strawberry Mousse – Decorating Idea

Basically, when you look at the cake from a side, in the place where you usually see the filling, you can see cut sides of strawberries halves. They create a lovely pattern and a simple but elegant finishing of the cake.

I didn’t see anywhere how to do this decoration, so I was ecstatic it worked for me perfectly the first time I made it.

However, I think it may have been beginner’s luck. So when I baked this cake for the second time, I took extra measures to ensure the decoration was not damaged, when I opened the tin. And using a new transparent plastic folder turned out to be a brilliant idea.

Although I baked this cake without any special occasion, I think it looks so good that it easily could be a birthday cake.


Sponge Cake with Strawberry Mousse [Birthday Cake]

Agnieszka Weiner
A classic sponge cake with strawberry mousse and a special strawberry decoration.
Prep Time 45 mins
Cook Time 40 mins
Total Time 1 hr 25 mins
Servings 10 people



  • 4 eggs separated,
  • 100 g icing sugar
  • 150 g plain flour
  • 0.5 tsp baking powder


  • 300 g strawberries (plus some more small, equal size strawberries for decoration),
  • 6 tbsp icing sugar
  • 2 tsp gelatin (heaped teaspoons)
  • 5 tbsp hot water
  • 300 ml double cream


  • Preheat an oven to 180 Celsius degrees (160 degrees for fan ovens).
  • Put a piece of baking paper on the bottom of a removable-bottom 18cm diameter cake tin (no need to cut a disc out, the edges can stick out as it will be easier to take the sponge out).
  • Put the egg whites into a big bowl, whisk them with an electric mixer till stiff, slowly add the icing sugar and beat a while longer.
  • Mix the egg yolks with a fork (just to break them), add to the whisked whites and gently stir.
  • Gradually add the flour mixed with the baking powder and gently stir with a spoon or spatula.
  • Pour the batter to the tin, put it to the hot oven and bake for 30-40 minutes until an inserted wooden stick comes out dry.
  • Liquidise the strawberries; press them through a fine sieve to remove the seeds, add 3 tbsp of icing sugar and stir.
  • Whip the cream with electric mixer until light and fluffy, add the rest of icing sugar (3 tbsp) and stir well.
  • Mix the gelatin with the hot water in a cup. If it doesn’t dissolve quickly, put the cup into a bowl with boiling water and stir constantly.
  • Add a few spoons of the liquidized strawberries to the dissolved gelatin, stir it and pour it to the rest of strawberries, stir again and gently combine with the whipped cream.
  • Take the cold sponge out from the baking tin and cut horizontally in half.
  • Cut open the plastic folder, so you have one big single-layered rectangle. Then cut in half along the longer side, so you end up with 2 long strips.
  • Line the sides of the tin with the plastic strips overlapping each other and place the bottom half of the cake back in the tin.
  • Cut the strawberries in half and start placing them one by one on the edge of the cake so that the cut part touches the plastic lining on the side of the tin. While you do it, press the strawberries gently into the cake, so they stay vertical.
  • Pour the mousse on top of the cake and spread it making sure the strawberries stay in place (next to the edge of the tin). You can keep a few tablespoons of the mousse and spread it on top.
  • Place carefully the top part of the cake on the mousse and decorate it with strawberries or the leftover mousse.
  • Put the cake to a fridge to set for at least 2 hours.
  • Before serving, take the cake out from the fridge, open and lift the side of the tin and gently remove the plastic strips. This way you can be sure the edges and the pattern will not be damaged.


You will also need 1 transparent plastic folder.
Tried this recipe?Let us know how it was!


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