Matcha Swiss roll

Instructions

1. Step 1

   Preheat the oven to 170°C and line the bottom and sides of a 25 by 35 cm rectangular pan with parchment paper, folding the corners so the paper hugs the pan. Fully lining the pan lets you peel off the thin sponge in one piece without tearing the edges. The pan is ready when the paper is flat, unwrinkled and has no gaps at the corners.

   Mark step 1 as done

2. Step 2

   Put 80 g egg yolks, 20 g granulated sugar and a pinch of salt in a bowl, whisk them together, then pour in 40 g vegetable oil and 50 g whole milk and stir well. The oil and milk make the sponge supple and soft, so it rolls without cracking. The mixture is ready when it's smooth, uniform in color and slightly thick.

   Mark step 2 as done

3. Step 3

   Sift 60 g cake flour and 8 g matcha powder together into the yolk mixture and stir gently until dissolved. Matcha clumps very easily, so sift it with the flour to spread the green color evenly. The batter is ready when it's evenly green, smooth and free of dark specks of matcha.

   Mark step 3 as done

4. Step 4

   Beat 150 g egg whites with 1 g cream of tartar, and once foamy, gradually add 60 g superfine sugar and beat until medium-soft peaks form. Meringue for a Swiss roll only needs to be softer than for a chiffon cake, so the sponge stays supple and easy to roll. The meringue is ready when it's glossy and smooth and the peak bends over clearly when you lift the beater.

   Suggested time: about 5 minutes.

   Mark step 4 as done

5. Step 5

   Mix a little of the meringue into the matcha batter to loosen it, then pour the batter into the meringue bowl and fold gently from the bottom up. Matcha contains natural oils that easily deflate the bubbles, so you need to fold quickly and decisively. The batter is ready when it's an even pale green, with no white streaks, and still light and airy.

   Mark step 5 as done

6. Step 6

   Pour the batter into the pan, spread it level right into the corners with a spatula, tap the pan twice, then bake at 170°C for 12 to 14 minutes. A short bake keeps the sponge soft and moist and preserves its bright green color. It's done when the top is dry, springs back when pressed lightly and the edges just pull away from the parchment.

   Bake at 170°C for about 12 to 14 minutes.

   Mark step 6 as done

7. Step 7

   Immediately flip the sponge onto a fresh sheet of parchment, peel off the lining paper, then loosely roll up the sponge together with the paper from the short side and let it cool for about 30 minutes. Rolling it while still warm helps the sponge remember its rolled shape, so it won't crack when you roll it the second time. It's ready when it has cooled and shows no cracks when unrolled.

   Suggested time: about 30 minutes.

   Mark step 7 as done

8. Step 8

   Sift 3 g matcha powder and 20 g powdered sugar into 200 g cold whipping cream and beat on medium speed until thick. The cream must be very cold to whip quickly and hold its shape when rolled. The cream is ready when it reaches medium-stiff peaks that stand up on the beater and is an even pale green.

   Mark step 8 as done

9. Step 9

   Unroll the sponge and spread the cream evenly over it, leaving it thicker at the end where you start rolling and thinner toward the far end, then roll it up tightly, using the parchment for support. More cream at the start creates a nicely rounded center in each slice. The roll is ready when it's evenly round, the seam is underneath and no cream squeezes out the ends.

   Mark step 9 as done

10. Step 10

    Wrap the roll tightly in the parchment, twist the ends and refrigerate for about an hour. Chilling sets the cream so the roll keeps its shape when sliced. It's ready when it feels firm when lifted and the cream inside is no longer soft and runny.

    Suggested time: about 60 minutes.

    Mark step 10 as done

11. Step 11

    Trim off both ends for a neat finish, then cut the roll into slices about two and a half centimeters thick with a warmed serrated knife, wiping the blade after each cut. A warm knife slices cleanly through the cream without squashing the cake. The slices are ready when the cut sides show a crisp green and white spiral.

    Mark step 11 as done