The sweet earthiness of matcha powder grounds this sophisticated take on an ice cream cone. Martha made this recipe on episode 508 of Martha Bakes.
Sift together confectioners' sugar, flour, matcha, and salt into large bowl. Make well in center. In a second bowl, whisk together butter, egg whites, cream, and vanilla until combined. Gradually add to flour mixture; stir until combined. Strain through a mesh sieve. Refrigerate batter, covered, at least 2 hours or up to overnight
Preheat oven to 375 degrees. Line two baking sheets with nonstick baking mats. Spray lightly with cooking spray. Place a 5-inch round stencil in corner of baking sheet. Using a small offset spatula, spread 1 tablespoon batter in a thin layer over stencil. Carefully lift stencil. Repeat, making a second round on the sheet. Bake just until brown around edges, about 5 minutes.
Working quickly, when cookies come out of the oven, use an offset spatula to transfer cookies, one at a time, to roll around a wooden reamer or tapered rolling pin to form a cone, or drape over a small bowl to create a bowl shape, if desired. (If cookies harden too quickly, return baking sheet to oven for 30 seconds.) Transfer to a wire rack, and let cool completely.
Repeat with remaining batter to bake and shape cookies. Once cookies are cool, fill as desired with ice cream just before serving.