Matcha Chiffon Cake

Ingredients

For 16 servings

• •4 ounces (113 g) egg whites from 4 large eggs
• •1 /2 teaspoon Diamond Crystal kosher salt; for table salt, use half as much by volume or same weight
• •142 g granulated sugar (5 ounces; about 2/3 cups), divided
• •128 g all-purpose flour (4 1/2 ounces; 1 cup)
• •1 c. à café baking powder
• •1 c. à soupe (5 g) matcha powder
• •56 g egg yolks (2 ounces) from 4 large eggs
• •56 g neutral oil (2 ounces; about 1/4 cup), such as vegetable
• •85 g cold seltzer or club soda (3 ounces; about 1/3 cup)
• •2 c. à café (10 g) vanilla extract
• •1 /2 cup mascarpone (4 ounces; 113 g)
• •2 tasse (480 ml) heavy cream
• •1 /4 teaspoon vanilla extract
• •1 /4 teaspoon Diamond Crystal kosher salt; for table salt, use half as much by volume
• •42 g powdered sugar (about 1 1/2 ounces; 3 tablespoons), plus more as needed
• •1 1/2 tablespoons (7 g) matcha powder
• •Powdered sugar, for dusting

Method

1. 1.For the Cake: Adjust oven rack to middle position and preheat oven to 350°F (180°C). Line a 13-by-18-inch rimmed baking sheet with parchment; set aside.
2. 2.In the bowl of a stand mixer fitted with the whisk attachment, combine egg whites and salt. Whisk on medium speed until egg whites begin to foam, then, with mixer continuing to run at medium speed, slowly and steadily pour in 1/2 cup sugar (100 g; about 3 1/2 ounces). Continue to whisk until meringue is glossy and reaches medium-stiff peaks, about 8 minutes.
3. 3.In a large bowl, whisk egg yolks, oil, seltzer, vanilla extract, and remaining 3 tablespoons sugar (42 g; 1 1/2 ounces) until smooth. Using a fine-mesh strainer, sift in flour, baking powder, and matcha, and whisk to combine. Pour 1/3 of the meringue into the yolk mixture, and gently whisk until homogeneous and smooth. Pour in the remaining meringue, and, using a flexible spatula, fold meringue into batter until well combined and no white streaks remain. Do not overmix: Batter should be light, fluffy, and voluminous. Clean the mixing bowl, then set it aside.
4. 4.Scrape batter onto prepared baking sheet and bake until cake is puffed, firm to the touch, but retains a slight indent when gently pressed, about 12 minutes.
5. 5.Remove cake from oven and immediately cover pan with two large strips of foil, using a kitchen towel or oven mitt to carefully crimp foil around the edges. Allow cake to cool to room temperature (approximately 70°F/21°C), 25 to 30 minutes.
6. 6.While Cake Is Cooling, Prepare the Filling: In the now-clean mixing bowl of the stand mixer fitted with the whisk attachment, whisk mascarpone on medium speed until smooth, about 1 minute. Add heavy cream, vanilla extract, and salt. Using a fine-mesh sieve, sift in matcha and powdered sugar. Whip on medium speed until stiff peaks form, 3 to 4 minutes.
7. 7.Uncover cake and, using a butter knife or offset spatula, loosen edges of the cooled cake. Using an offset spatula, spread mascarpone and cream mixture into an even 1/2-inch-thick layer over the cake. (You may have extra filling; that is OK. Reserve for another use.)
8. 8.Position the cake so the long end is closest to you. Using the parchment as a handle, lift that edge of the cake and make a gentle first fold (about 1 inch) so the cake starts to curl over itself. Keep rolling away from you, using the parchment to lift and guide the cake into a tight, even spiral; the parchment will naturally peel away as you go.
9. 9.After rolling, transfer the cake seam side down to a large platter, dust with powdered sugar, and, using a sharp chefs knife or serrated knife, portion into 1-inch slices. Serve right away. (For cleaner cuts, wipe knife with a kitchen or paper towel before portioning each slice.)