Moist and soft chocolate Swiss roll recipe

It's been a while since I last baked a cake. I was thinking of sponge cake but felt like trying something new. What came to my mind was…a Swiss roll! After all, they are a kind of sponge cake.

I always thought that a sponge cake recipe can be used to make any shape of sponge cake. Hence, I was tempting to modify the Hokkaido sponge cupcake recipe for making a Swiss roll. However, after doing some research especially after reading Kitchen Tigress's scientific explanation on making a Swiss roll, I was convinced that it is not the case. In the end, I decided to follow the most convincing chocolate Swiss roll recipe from Kitchen Tigress with some modifications. I merely replaced water with milk and reduced the amount of sugar as well as slightly modified the steps.

I've actually baked the Swiss roll twice now. I used an Ikea baking tray with the size of 37 x 25cm which is roughly about 14.5 x 10 inches. On my first attempt, I scaled the ingredients to the right ratio according to the recipe. The sponge cake was moist. The crust wasn't sticky and it didn't crack when it was being rolled. However, I found the cake a bit too thin as it's only about 1cm thick. So for my second trial, I doubled the original recipe and still used the same baking pan. It resulted in a slightly thicker cake of about 1.5cm thick. The sponge cake maintained the same moisture as the 1st attempt and I like this thickness. The only problem was the difficulty when rolling. In fact, it cracked while rolling (I probably pressed too hard?!). Even with the minor cracks, I still prefer a thicker Swiss roll. ;)

As for the filling, I decided on a light vanilla whipped cream with some fresh strawberries to balance out the sweetness of the chocolate cake. Not only the cake was delicious, the texture was almost perfect too! Looks like I'll stop buying Swiss rolls from the bakery now! 

Recipe: 

The sponge cake:

(I used a 37x25cm cake pan, original recipe asked for 18”x12”)

30g vegetable oil

20g Dutch cocoa powder

20g castor sugar
60g egg yolks

20g milk

pinch of salt

½ teaspoon vanilla extract

30g cake flour

140g egg whites

55g castor sugar   

1. Heat the vegetable oil until hot but not until smoking point.

2. Pour hot oil onto the cocoa powder in a mixing bowl and leave it aside to cool.

3. Whisk egg yolks and sugar in a mixing bowl until pale and thick.

4. Add milk, salt, vanilla extract and stir to combine.

5. Add cocoa mix and stir thoroughly.

6. Sift half the cake flour into the mixture and mix evenly. 

7. Sift the remaining cake flour into the mixture and mix evenly. Leave the mixture aside. 

8. Beat the egg white in another mixing bowl.

9. Gradually add in the sugar when the egg white starts to thicken. Beat until firm peak stage.

10. Loosen the egg yolk mixture by slowly stirring the mixture from the bottom of the mixing bowl using a whisk. 

11. Add the egg white mixture onto the egg yolks mixture in 3 batches. Mix until they are almost combined on each addition. Lastly, scrape down and fold until everything is evenly combined. 

12. Grease the cake pan and line cake pan with parchment paper. The length of the parchment paper should be the same length of the cake pan but the width should be slightly longer so that the batter would directly contact with only 2 sides of the cake pan. Example: use a 12”x12” parchment paper on a 12”x10” cake pan.

13. Pour batter onto the cake pan and spread the batter evenly. Lightly bang the cake pan on the table top twice to release the air bubbles. 

14. Bake on the middle shelf in a pre-heated oven at 200c for about 10 minutes. 

15. Remove the cake from the oven; lightly bang the cake pan on the table top a few times.

16. Unmould the cake and let it cool on a wire rack with the parchment paper peeled from the sides of the cake but still intact with the bottom of the cake. 

Whipped cream:

150ml whipping cream

3/4 tablespoon castor sugar

A few drops of vanilla extract

Note: adjust the amount of sugar according to taste. I deliberately reduced the sugar because I think the cake is sweet enough for me. 

1. Pour whipping cream onto a chilled mixing bowl over a bowl of ice water. Add in sugar and vanilla extract. Beat until the cream is stiff.

To assemble the cake:

Cut strawberries

1. Flip the cake around and place the top of the cake on a clean sheet of parchment paper. Carefully remove the old parchment paper that was attached to the cake after baking. 

2. Spread the whipped cream evenly on the cake. 

3. Sprinkle the cut strawberries evenly on the whipped cream layer. 

4. Gently roll the cake with the parchment paper. 

5. Chill the cake in the fridge with the parchment paper until the filling is set. 

6. Cut and serve.