Why It Works
- Slowly adding the sugar to the egg whites while whipping ensures it will dissolve properly.
- Whisking the meringue at a lower speed for longer results in a stronger, more stable foam that’s less likely to deflate.
- Seltzer lightens the dense paste of egg yolks, oil, and flour to minimize deflation of the meringue as you fold the cake batter.
When I lived in Toronto, there was a Japanese coffee shop called NEO Coffee Bar several blocks away from my apartment. They made exquisite sweets and sandwiches: Their glass case was filled with sandos, mochi, choux pastries, and roll cakes. I spent hours there reading, sipping on hojicha lattes, and nibbling on their matcha roll cake, a tender, bittersweet green chiffon sponge swirled with lightly sweetened whipped cream. It’s been almost a decade since I’ve lived in Toronto, but I still think about that matcha cake.
Inspired by the cake I miss so much, I decided to make my own. Like all chiffon cakes, I separate the egg yolks and whites, whip the whites with sugar until they’ve doubled in volume, then gently fold them into a mixture of egg yolks, oil, and the dry ingredients. The recipe below borrows from former editor Stella Parks’ classic chiffon cake recipe: I use a similar ingredient ratio but tweak the method slightly.
Serious Eats / Qi Ai
Whereas Stella starts her batter by combining egg whites and all the sugar from the get-go for a dense meringue, I take a different route by dividing the sugar: I reduce the amount added to the egg whites and incorporate the sugar gradually to create a slightly lighter foam that’s both easier to fold with the remaining ingredients and spread into a even layer when it goes into the rimmed baking sheet. That consistent thickness is crucial for rolling the cake later and will give you the most uniform swirl.
Another essential element of making the batter is the kind of matcha you use. I recommend using a good-quality matcha powder, as that will determine how flavorful your cake will be. Whichever route you go, be sure the matcha you use isn’t blended with sugar or milk powder, as that introduces variables you can’t control for and will impact how your cake turns out. Last but not least: Sift, sift, sift. A lump or two of matcha won’t make or break your cake, but it’s worth taking the time to sift the matcha—along with the flour and baking powder—for the smoothest possible batter.
Serious Eats / Qi Ai
Once the cake is baked, you’ll want to keep it nice and moist so it stays pliable for rolling. This may be the most intimidating step, but I assure you it’s anything but, thanks to one of Stella’s clever tricks. Simply cover the rimmed baking sheet with foil to tightly seal the cake once it comes out of the oven, which will trap steam as the cake gradually cools. Once the cake is thoroughly cooled, it’ll still be moist and pliable enough to roll.
Though the matcha cake I love so much from NEO Coffee Bar is filled with lightly sweetened whipped cream, I wanted to give it even more matcha flavor by incorporating the tea into the filling as well. On its own, whipped cream is very light and can be tricky to roll without making a big mess. Here, I include mascarpone, which provides a subtle tanginess and just enough structure to make rolling and assembling the cake a touch easier.
Now I need to perfect my hojicha latte game.
