Line a cookie pan with baking paper. Cut the paper slightly bigger than the actual size of the tin. Make small slits at corners and line the pan.
Preheat the oven to 355°F/180°C. Shift together the flour and baking powder. Separate the egg yolks and whites.
Whisk the egg whites. At first without adding sugar, whisk until stiff peaks are formed. Divide the sugar into three portions and whisk well after each addition.
You will have a shiny and smooth meringue. When you lift the whisk, if stiff peaks are formed and it doesn't collapse, it's done.
Add three egg yolks and whisk until fluffy as showed in this photo.
Shift again the flour and matcha and add to Step 5. At this point, heat the cream over a bain marie.
Stir the mixture gently and well by lifting from the bottom of the bowl and folding in.
After the flour is mixed in, pour in the warmed cream gently using a plastic spatula and mix well as you did at Step 7.
Pour in the batter into the pan and flatten the surface evenly with a palette knife. Tap the tin several times to remove excess air.
Bake in the oven at 355°F/180°C for 11 to 12 minutes until the skewer inserted in the middle comes clean.
Remove the pan from the oven and lay on a cooling rack. Cover with kitchen paper or tea towel and leave to cool.
Meanwhile, make the adzuki cream. Whisk the cream until a soft peak is formed and add the adzuki beans. Whisk again.
Do not over-whisk the cream, otherwise it will separate. Chill the finished cream in the fridge.
After the sponge cake has cooled, peel off the baking paper off. Gently peel off 3 cm border at the closest end.
Place the sponge onto a slightly bigger paper or work surface (at this point, the paper of the sponge bottom is still attached).
Spread adzuki cream from Step 13 evenly on the sponge, leaving a 1 cm border at one end with less cream.
Lifting the paper at your end, fold in the end of the sponge.
Roll the sponge over by pulling the paper, ensuring that the sponge is rolled tightly.
In this method, the baking paper is peeled off as you roll the sponge and the joint comes under the rolled sponge. Wrap the rolled sponge with a big piece of cling film.
Leave to rest in the fridge for at least one hour and you will have a delicious Swiss roll.
Story Behind this Recipe
I tried different recipes to make delicious Swiss rolls and finally I came up with this recipe. With this recipe, you will have a fluffy sponge and be able to roll easily without damaging. This sponge also doesn't dry out quickly. This time I wanted to use adzuki cream so I made a green tea-flavoured sponge.
After adding the flour at Step 7, stir the mixture 50 to 60 times (if you get used to it, 80 times) and you will have a smooth sponge. I used Imuraya brand's sweet cooked adzuki beans. If the adzuki beans are too runny, microwave for 30 seconds to remove the excess moisture.