Green Tea-Ginger Marshmallow Shortbread

Preparation

1. Step 1

   Heat the oven to 325 degrees. In a food processor fitted with a blade, pulse together flour, sugar and ¾ teaspoon salt. Add the butter and pulse to fine crumbs. Pulse a few more times until some crumbs start to come together, but do not overprocess. Dough should not be smooth. Press dough into an ungreased 9-by-13-inch baking pan. (It won’t look as if you have enough, but keep pressing and it will cover the pan in a thin layer.) Prick dough all over with a fork. Bake until golden brown, 35 to 40 minutes. Transfer to a wire rack and cool completely.

2. Step 2

   In a small bowl, whisk the gelatin and matcha together. Stir in 1 cup cold water. Rest the mixture until it thickens.

3. Step 3

   In the bowl of an electric mixer, whisk the egg whites and the remaining ¼ teaspoon salt on medium speed, until soft peaks form, about 4 minutes. Stop the mixer.

4. Step 4

   In a saucepan over medium heat, cook the granulated sugar, honey and 1 cup water, stirring until the sugar dissolves and the mixture reaches 240 degrees on a candy thermometer. Start the mixer on medium-high and carefully pour the hot syrup down the side of the mixing bowl into the whites in a slow and steady drizzle. Continue mixing until the mixture has cooled slightly, about 2 minutes. Scrape in the gelatin mixture. Continue mixing on medium-high speed until the mixture begins to thicken and quadruples in volume, about 10 minutes. Scrape the mixture into the pan with the shortbread, smoothing the top with an offset spatula. Rub together the candied ginger and superfine sugar to break up any clumps. Sprinkle over the top of the marshmallows. Let marshmallows set for 4 hours or overnight at room temperature. Cut into squares.