水玉点点蛋糕卷 Polka Dot Roll Cake

Pattern/deco roll cakes have been on my to-bake list for the longest time. As a cookbook junkie, I've hoarded three books on Japanese-style pattern/deco roll cakes already - 彩绘蛋糕卷 by Sachi and 彩绘.蛋糕卷 1 and 彩绘.蛋糕卷 3 by Junko. Have always been very inspired by the Japanese way of styling and decorating their baked creations, and so have been salivating over the photos in the books but somehow always procrastinating, never get down to bake them :p

Then recently SCS Dairy Singapore announced a Star Baker Challenge 2014, where avid bakers could participate in baking challenges through 5 different stages. The 1st stage is open category, simply submit a photo of a baked creation to the official website and valid entries would be awarded with SCS 1-Star Baker status! Subsequently there would be themed challenges and invited participants who are successful would be awarded 2-Star, 3-Star, 4 Star certificates progressively. Eventually a final round where winner would be awarded an all-expenses-paid trip to Australia for two; whereas consolation prize winners would receive culinary vouchers at Palate Sensations! Finalists would also receive trophy, customized SCS apron, baker's kit and 5-Star Baker certificate. Ooooh, how cool does all these sound?

Well, I don't think I would make it very far, but at least I could try for 1-Star as a challenge for myself :) Was thinking hard what I  should bake for the first submission? Should I go for something tried and tested like strawberry shortcake, lychee ombre cake or rainbow cake? Although I was running tight schedule this week coz travelling next week, my heart told me to try something new. There, I've got the perfect motivation to try the pattern roll cake :)

Junko and Sachi used different methods to bake the patterns and sponge. Basically Junko's method is whipping egg whites separately and then folding into main batter; whereas Sachi uses bain marie (hot water bath) method to whip full eggs batter for aeration. Since the prerequisite is butter, I used Sachi's recipe that requires butter (Junko uses oil only).

For the pattern, something simple to start with, one of my favourite, the polka dot! As for the deco, I had some whipped cream, strawberries and mint leaves left in the fridge, just the right combination I need to achieve the kawaii Japanese-style of roll cakes.

Started quite late in the afternoon so was kind of rushing through, only managed a few photos of the process. Didn't prepare the pattern batter well enough and the dots looked a little "detached" from the sponge cake. I suspect the batter might be too thin. The recipe states that I should heat the butter and oil using bain marie method and beat till texture resembles mayonnaise. Quite puzzling coz once butter melts, how would it turn into mayonnaise texture? I tried and failed and decided to continue using the melted butter/oil resulting in slightly runny batter. Next time, I should just mix softened butter with oil (without any heat) to get the mayonnaise texture and probably the batter would be stiffer.

Anyways, I piped the polka dots free-hand :p There's a free pattern at the back of the book to use as guide but I didn't want to cut out the page :p (probably next time I should trace or photocopy the patterns).

The sponge cake was not as refined as I want it to be, could have beaten the batter longer time at lower speed. Nevertheless, very glad that the sponge cake didn't crack or anything. I must say this method of baking sponge cake yielded very tender texture (actually quite similar to my rainbow cakes) and I could probably adapt this recipe for my rainbow cakes as well.

Love the cheery, summer colours of the roll cake and the overall visual effect, very Nihon-looking, yeah =D
It was absolutely delish and not too sweet. Given thumbs up by both hubby and the kiddo. I'm definitely tempted to try more pattern roll cakes, hopefully soon as I have an ever-growing list of recipes bookmarked :p

Polka Dot Roll Cake
(makes one 9" by 9" roll)

Part I - Polka Dot batter

• 25g cake flour (I use Nissen Violet flour)
• 25g unsalted butter
• 1/2 tsp oil (any neutral tasting oil like canola, sunflower or grapeseed)
• 20g icing sugar
• 15g egg whites
• Pink icing gel (I use Wilton)

1. Line baking parchment on a 9" by 9" tray. If using pattern guide for tracing, place the guide under the parchment. Set aside. (original recipe uses 8" by 11" tray)
2. Sift flour and set aside.
3. In a heatproof bowl, heat butter and oil over hot water bath till butter is melted and combined with oil. (suggest to combine softened butter and oil without heat for better result)
4. Remove bowl from heat. Add icing sugar and stir till well blended.
5. Add egg whites and mix well.
6. Add flour and mix well. A sticky and thick batter will form.
7. Use a toothpick to pick up a bit of pink icing gel and mix into batter. Adjust colour to desired tone.
8. Prepare a piping bag with 5mm round tip. Pipe 1cm circles/polka dots at regular intervals onto the parchment paper prepared in (1).
9. Place tray into fridge/chiller for 15-20 mins for the polka dots to firm up.

Part II - Sponge Cake

• 30g cake flour (I use Nissen Violet flour)
• 10g corn flour
• 15g unsalted butter
• 10g fresh milk
• 3 eggs (55g to 60g eggs, about 160g in total)
• 15g light corn syrup (book uses ingredient called 水饴 which I'm not sure so I used light corn syrup)
• 45g caster sugar

1. Preheat oven (top and bottom heat) to 200 degree celsius.
2. Sift cake flour and corn flour together 2 times. Set aside.
3. In a heatproof bowl, heat butter and milk over hot water bath till melted and combined. Set aside to cool down.
4. In a mixing bowl, add eggs, light corn syrup and caster sugar and whisk together.
5. Place the mixing bowl over hot water bath and continue whisking the mixture till foamy and very hot to touch. Do not stop whisking else the mixture would be cooked and lumpy.
6. Transfer mixing bowl to electric mixer and beat at high speed using whisk attachment, till batter becomes glossy and slightly thicker than ribbon stage (when batter is lifted, it drops back very slowly and stays on top of the batter surface).
7. Add flour mixture from step (2) into the batter, little by little over 4-5 times. After each addition, FOLD the flour into the batter very gently.
8. Once all flour added, FOLD gently about 20 times to make sure thoroughly incorporated.
9. Take a small batch of batter (about 2 scoops) and FOLD into butter/milk mixture from (3) till incorporated.
10. Pour the small batch of batter from (9) back into the main batter. FOLD gently about 40-50 times to make sure thoroughly incorporated.
11. Remove tray with polka dot pattern from fridge and gently pour the batter from (10) onto the tray.
12. Make sure the batter is evenly distributed, use plastic card/scrapper to level if needed.
13. Bang the tray onto counter-top 2 times to remove trapped air bubbles from the batter.
14. Place tray into oven and bake at 180 degree celsius for 12-13 mins.
15. Once ready, remove baking tray from oven and bang it onto counter to prevent sponge cake from shrinking.
16. Remove cake from tray, place onto a cooling rack. Place another cooling rack on top of the cake and flip the cake to the other side. Remove the baking parchment gently (the polka dot design will be revealed). Let the cake cool down before assembly/decoration.

Part III - Chantilly cream - Assembly/Decoration

• 250g dairy whipping cream
• 50g mascarpone cheese
• 25g icing sugar
• Strawberries, mint leaves

1. Place mixing bowl and whisk attachment in chiller for at least 30 mins, this will help in whipping the cream.
2. Place the sponge cake onto a piece of parchment paper, pattern side down.
3. At the side nearest to you, trim the edge of the cake at a 45 degree angle.
4. Make slight vertical indents using a knife onto the surface of the cake. This will help in the rolling.
5. Whisk cream together with mascarpone cheese and icing sugar till medium firm peaks. Be careful not to over-whip.
6. Prepare 2 piping bags with round tip (8mm) and close star tip and fill with chantilly cream. Set side.
7. Spread a thin layer of chantilly cream over the entire surface of the sponge cake.
8. At the 1/3 area of the sponge cake (nearer to you), pipe 4 lines of cream across the cake, then 3 lines on top of the 4, then 2 lines (like pyramid).
9. Ready to roll, lift the cake and parchment paper (side nearer to you) and roll towards the other side of the cake.
10. Wrap the parchment paper around the roll, press a ruler by the side of the roll to tighten.
11. Place roll into chiller for at least 30 mins to firm up.
12. Remove the roll from the chiller, unwrap parchment paper. Warm up a sharp pastry knife and carefully trim both sides of the roll cake.
13. Pipe some chantilly cream using the close star tip onto the roll cake and decorate with cut strawberries and mint leaves.
14. Best serve chilled.

Besides the SCS Star Baker Challenge 2014, the Singapore Home Cooks (SHC) Facebook group is also running a June contest where participants stand a chance to win SCS Baker's Kit :)

Wish me luck!

This post is linked to the event Little Thumbs Up (June 2014 Event: Butter) organised by Zoe (Bake for Happy Kids) and Mui Mui (My Little Favourite DIY) and hosted by Jozelyn Ng (Spice Up My Kitchen)