DIRECTIONS
- In a medium bowl whisk to combine flour, baking powder, and salt.
- In a large bowl or the bowl of a stand mixer fitted with the paddle attachment, beat butter and ⅔ cup sugar until light and fluffy. Beat in egg and vanilla until combined. Add flour mixture and mix until just combined and the dough is smooth.
- Transfer dough to a countertop and divide in half. Return half of the dough to the mixer or bowl. Add matcha powder to bowl and gently mix in until dough is an even green color. Remove dough from bowl.
- Grind raspberries in a spice grinder or with a mortar and pestle, then sift through a fine-mesh sieve to remove the hard seeds.
- Add other half of dough to mixer, mixing in 1 tablespoon raspberry powder. If the doughs are very soft, cover tightly and refrigerate for 1 hour before proceeding.
- Roll the matcha and raspberry doughs out into ⅛” thick rectangles of about 10×7”. Stack one dough on top of the other, and, starting with a long edge, roll up tightly like a jelly roll. Gently roll dough back and forth on work surface, starting with your hands in the center and moving outwards, to roll dough into a 16” long log. Roll dough in remaining ½ cup sugar to coat the outside. Wrap dough tightly in plastic wrap and refrigerate or freeze until firm, 1-2 hours.
- Preheat oven to 350℉. Line 2 sheet pans with parchment paper.
- Cut dough into ¼” thick slices and transfer to prepared sheet pans, leaving 1” between cookies. Bake until very lightly browned, about 10 minutes. Let cookies cool on sheet pans for 3 minutes, then transfer to racks to cool completely.
- In a double boiler or heatproof bowl set over a saucepan with 1” of water, melt white chocolate over steaming (not simmering or boiling) water, stirring constantly.
- Dip half of each cookie in white chocolate, placing cookies back on lined sheet pans. Sprinkle white chocolate with remaining raspberry powder. Refrigerate to firm chocolate, about 15 minutes.
- Store cookies in an airtight container at room temperature for up to 2 weeks.
