Sift the A) ingredients, cake flour, cornstarch, ground tea leaves. Preheat the oven to 160℃.
Heat up the milk to a high temperature and drop the tea bag in it to brew strong tea. Take out the teabag, add the butter, and melt. You can use a microwave or a pan to do this process.
Then whip the egg whites. Add the sugar in 2 batches and keep whipping until the mixture forms stiff peaks as shown in the photo.
Using the same hand mixer (no need to wash it), mix the egg yolks in a different bowl. Add the dry ingredients from Preparation 1 and milk tea from Preparation 2 and mix really well, until they become like runny mayonnaise.
Add the stiff meringue from Step 3 in 3 batches. Mix with a whisk as shown in the photo.
Stir the mixture by lifting from the bottom of the bowl and folding in with the whisk (not the hand mixer!).
Line a baking tray with parchment paper, fold its 4 corners and secure with a staple.
Pour in the batter from Step 6 and bake on the middle rack of the oven at 160℃ for 10~15 minutes. Don't open the oven before 10 minutes. Insert a toothpick in the center and if it comes out clean, it's done.
Take out from the oven and cool the sponge cake. Spread the whipped cream on the cake, and start rolling up from the 24 cm side. If you put something inside, start rolling up from the 35 cm side.
When you finish rolling it up, wrap the rolled cake with a new piece of parchment paper and aluminum foil on top. Then wrap with a bamboo sushi mat and chill in the fridge for more than 2 hours.
This time, I used the whipped cream with vanilla extract, but it's also delicious if you add a teaspoon of cointreau instead.
Story Behind this Recipe
I love sweet royal milk tea, milk tea that is made by brewing tea leaves in milk, so I made this roll cake using it.
Make a stiff meringue, and don't be afraid to mix the meringue and egg yolk mixture really well. Doing so will give you a fine textured sponge cake . Please adjust the cooking time depending on your oven. Don't bake too much. It's so moist and fluffy because the sponge cake is made using a lot of milk!!