Green Tea (Matcha) Souffle Roll Cake with Purple Sweet Potato Paste

“What a long description.” I thought when I was typing the title for this blog. But I really have to give justice to  the purple sweet potato, especially for its performance in this desert.

I found an alternative way of preparing swiss roll, or I would rather use the term ‘roll cake’.  The outcome turned out to be a softer, more moist texture that suits more to our taste.

Matcha or green tea, has an slightly bitter after-taste that my family do not really like. It is an acquired taste. So I decided to use the purple sweet potato as the filling for its sweetness instead of the usual whipped cream. First of all, I am a die-hard fan of these purple beauties. And also, we decided to embark on something more healthy lately.

Ingredients (make one 28 cm roll cake)

A) Souffle roll sponge

• 1        egg
• 3        egg yolks
• 1tsp   vanilla extract
• 35g    unsalted butter
• 60g    pastry flour, sifted twice
• 10g    green tea (matcha) powder, sifted
• 60ml  fresh milk
• 3         egg whites
• 85g    caster sugar
• One 28 x 28-cm flat square cake pan

Instructions

1. Preheat oven to 180 degree C. Line cake pan with parchment paper or natural drawing paper.

2. Combine egg, egg yolks and vanilla extract in a small bowl and beat lightly. Set aside.

3. Sift the pastry flour and green tea (matcha) powder. Set aside.

3. Place butter in a small saucepan, and heat gently until melted. Add flour mixture to melted butter and cook through. Transfer butter-flour mixture in a bowl and add the egg mixture a little at a time. With a spatula, mix into a smooth batter.

simply love the colour of the cooked mixture

 4. Add milk and mix to incorporate. Strain batter and set aside.

5. To make meringie, place egg whites in a clean bowl and beat until foamy. Add half the sugar and continue beatimg until just incorporated. Pour batter into prepared cake pan and spread evenlywith a scraper. Place cake pan on a tray and bake for 20 minutes.

6. When the souffle roll sponge is done, remove from pan and place in a big plastic bag to cool.

This souffle roll has more moisture than the usual Swiss roll

Note :

1. The gluten content of the flour makes the sponge hard. Cooking flour with butter weakens the gluten content in the flour, resulting in a light, bouncy and fluffy cake.

2. Important for the meringue to be stiff and stable for the souffle roll sponge to rise.

B) The paste

• 400g  purple sweet potato
• 100ml  of fresh milk

Instructions

1. Steam the purple sweet potatoes till they are soft. Mash them up to form a paste.

2. Add in the fresh milk to the paste and mix well. The final product should be a smooth paste that could be used as a spread. If the paste is still dry, add in somemore milk to smoothen it.

Assemble

1. Turn cooled souffle spong onto a clean work surface. Peel off the parchment paper from the bottom of the sponge.

2. Spread the paste bin an even layer over the sponge.

3. Gently roll up sponge to make a swiss roll. Place in the freeze to chill and set before serving.

The colour combination turned out to be so contrastingly attractive. Wow.

This has became one of my parents’ favourite snack. All the while, they do not have a liking towards green tea. And this combination actually suits their taste. The paste covers the unique bitterness of green tea (matcha) in a modest manner. The natural sweetness of the paste enhances the taste of this snack.

Most interesting of all, busy grandmom actually asked me for the recipe. This is not too bad for my first attempt in making souffle roll cake.