For Cake:
- Preheat the oven to 375ºF. Grease or butter a 15” x 10” jelly roll pan then line with parchment paper. The grease will help the parchment paper stay put on the pan.
- Separate the egg yolks and whites into two bowls. Keep the egg whites in the refrigerator, and the egg yolk at room temperature.
- Using a fine-mesh sieve, sift the Swans Down Cake Flour, baking powder, and matcha powder over a sheet of parchment paper.
- Transfer the dry ingredients into a bowl, set the sieve over the parchment paper and sift 2 more times (total 3 times).
- In a separate large bowl, whisk the egg yolks until smooth. Add half of the sugar (¼ cup) and whisk until the egg mixture doubles in volume. When you lift the whisk into the air with some of the mixtures on it, the mixture should fall back into the bowl in ribbons, which slowly disappear back into the mixture. Set aside.
- Add the cold egg whites into another large bowl. With an electric hand mixer (or stand mixer), beat the egg whites until foamy.
- Gradually add the remaining sugar (¼ cup) over three separate times and beat until still peaks form and egg whites are glossy.
- Gently whisk in ⅓ of the egg whites to the egg yolk mixture until incorporated in the batter.
- Then add the mixture back into the egg whites. Gently fold in egg whites with a silicone spatula.
- Add the dry ingredients. Using the silicone spatula, fold in gently until just incorporated. Do not over mix!
- Add the warm milk and fold in until incorporated.
- Pour the batter into the prepared pan. Spread the batter evenly.
Bake the Cake:
- Tap the jelly roll pan a few times on your working surface to remove the air bubble inside the batter. Bake for 10-12 minutes, or until an inserted toothpick comes out clean and the top of the cake springs back when touched. Make sure not to over bake or the cake will be too dry and break when you roll.
- Cool your cake for 2-3 minutes on the baking sheet. Lay a fresh sheet of parchment beside your cake and sprinkle it with powdered sugar.
- Remove from pan and Flip the cake onto the sugared parchment paper. Remove old parchment paper from the flipped cake.
- While the cake is still warm, use your hands to slowly roll the cake on the sugared parchment paper. Once the cake is rolled up, transfer to a wire rack.
- Cover with a kitchen towel and let it cool completely (until it reaches room temperature, about 30 minutes).
Make Whipped Cream Filling:
- Combine cold heavy cream and sugar in a large bowl. Beat until firm and spreadable, so it won’t ooze out of the cake when you’re rolling it up.
Assemble the Cake:
- Transfer the swiss roll to a flat surface and unroll the cake. It’s okay if the ends curl up a bit.
- Using an offset spatula, spread the whipped cream mixture evenly over the cake, leaving a ½-inch border on all sides. A little tip: Spread slightly less amount of filling toward the last ⅓ of cake as the cream will pile up toward the end when rolling up.
- Carefully but tightly re-roll the cake. The seam side should be on the bottom. Once you roll up the cake, secure the roll by twisting the parchment paper at both ends (like a candy wrapper). Refrigerate for at least 2 hours to firm up the cream.
- Remove and unwrap the Swiss roll. Slice o about ½ inch of the cake on both ends (to show o beautiful swirls). Transfer it to your serving dish. Slice and serve.