Prepare the Matcha Cake Sheet
Preheat the oven to 350°F (175°C).
Line a 12 x 17-inch baking tray with parchment paper and set aside.
Mix the Dry Ingredients
In a small bowl, whisk together the cake flour, sifted matcha powder, and baking powder. Set aside.
Separate the Eggs
Carefully separate the egg whites and yolks into two large mixing bowls.
Make the Meringue
Add the cream of tartar to the egg whites.
Beat on low-medium speed until frothy.
Gradually add 100 g of sugar, one spoonful at a time.
Continue beating on medium-high speed until stiff peaks form.
Prepare the Egg Yolk Batter
Add the remaining 50 g sugar to the egg yolks and mix until combined.
Add the milk, oil, and vanilla extract and mix well.
Sift the flour mixture into the egg yolk mixture.
Mix on low speed until just combined.
Fold the Batter
Fold one-third of the meringue into the yolk mixture using a spatula.
Gently fold in the remaining meringue until no streaks remain.
Be careful not to overmix the batter.
Bake the Cake
Pour the batter into the prepared baking tray.
Spread evenly with an offset spatula, ensuring the batter reaches all corners.
Bake for 12–15 minutes, or until the cake is lightly browned around the edges and springs back when touched.
Release and Pre-Roll the Cake
Cool the cake for about 5 minutes on a wire rack.
Run a spatula around the edges to release it from the pan.
Invert the cake onto a wire rack and carefully peel away the parchment paper.
Place a fresh sheet of parchment paper on top and flip the cake over again.
Trim the browned edges from the two short sides.
While still warm, roll the cake up with the parchment paper starting from the short end.
Allow the rolled cake to cool completely.
Make the Matcha Whipped Cream Filling
In a large bowl, sift in the matcha powder.
Add a small amount of whipping cream and mix into a smooth paste to remove any clumps.
Add the remaining whipping cream, powdered sugar, and vanilla extract.
Whip until stiff peaks form.
Assemble the Swiss Roll
Carefully unroll the cooled cake.
Spread an even layer of matcha whipped cream over the surface.
Leave approximately 2 inches of cake uncovered at the far end.
Reserve any extra whipped cream for decoration.
Roll and Chill
Roll the cake back up tightly in the same direction as before.
Wrap securely in plastic wrap.
Refrigerate for at least 3 hours or overnight to set.
Serve
Trim about ½ inch from each end to reveal the spiral pattern.
Slice into 1–1½ inch pieces.
Decorate with any remaining whipped cream before serving if desired.