Purple Sweet Potato Swiss Roll

It's the end of the month again, just a couple more days before we enter August and here I am scrambling to post my third and final entry for this month's Aspiring Bakers Event. For this month's event, everyone is challenged to try their hand  in swiss roll making. Most home bakers are intimidated by swiss rolls. I was too. Though baking the cake itself is easy, most dread when it comes to rolling for fear of the cake tearing. From my own experience and from other bloggers too, I found recipes that use egg white separation method (ie. chiffon cakes) make cakes that are springier and more flexible for rolling.

Here I made a Purple Sweet Potato Swiss Roll, adapted from a chiffon cake recipe. Just look at that lovely soft  purplish lavender hue ... it's all natural, no artificial coloring was added.  So pretty, so sweet and so girly, don't you think. The more I look at it the more besotted I am with the colour.  The swiss roll was yummy too. Soft, moist, and light.   

I am submitting this entry to Aspiring Bakers #9 - Swiss Rolling Good Times (July 2011) hosted by Obsessedly Involved with Food.


Purple Sweet Potato Chiffon Roll
(Recipe adapted from 'Little House' here)

Note: I have slightly altered  the recipe from the original to include an extra egg yolk, and baked the cake in a swiss roll pan instead of a chiffon cake tin.

Ingredients:

100g purple sweet potato

6 tbs milk

4 egg yolks

20g brown sugar

1/8 tsp salt

50ml canola oil

85g cake flour

4 egg whites

50g white sugar

1/2 tsp cream of tartar

Method:

- Preheat the oven to 350F (177C).

- Wash the sweet potato well and steam until very soft. Using a fork, mash the sweet potato with milk  or alternatively, blend in a food processor until smooth. 

- Whisk together the egg yolks, brown sugar, salt and oil until combined. Add the sweet potato mixture and beat until blended and smooth. Sift in the flour and beat until smooth. 

- In another bowl, beat the egg whites, sugar and cream of tartar until stiff and glossy peaks formed. Add 1/3 of the beaten  egg whites to the yolk mixture and gently mix to loosen a little, then gently fold in the rest of the beaten egg whites until well combined and smooth.

- Pour the batter into a lined (12 x12 inch) swiss roll pan. 

- Place the pan into the oven and bake for 15-20 minutes or until the cake is cooked through (test with slewer).
-  Lift cake from  pan and let cool on a wire rack.
- Once cooled, turn cake on a  clean baking paper and remove the lining. Invert it again. Carefully scrape/slice away the skin.  Spread filling of your choice.  Roll up, trim away the ends. Done!