01 -
Whisk glutinous rice flour, cornstarch, sugar, and milk in a microwave-safe bowl until smooth. Cover loosely and microwave for 1 minute, stir, then microwave in 30-second bursts until thick, sticky, and slightly translucent, about 2-3 minutes total.
02 -
Let the mochi cool for 2 minutes. Rub a spatula or gloved hands with a little oil, then knead in the softened butter until smooth. Cover tightly and let it cool while you make the cookie dough.
03 -
Beat butter and brown sugar until creamy, about 1 minute. Mix in the egg and vanilla. Add flour, sifted matcha, baking powder, and salt, then fold until a soft green dough forms.
04 -
Flatten the dough into a disk, wrap, and chill for 30 minutes. Heat the oven to 350°F (175°C) and line two baking sheets with parchment paper.
05 -
Divide the mochi into 16 small pieces and the cookie dough into 16 pieces. Flatten one dough piece, place mochi in the center, and wrap the dough around it. Seal well and roll gently.
06 -
Place cookies 2 inches apart on the baking sheets. Press each cookie slightly flatter and add white chocolate chips on top. Bake one sheet at a time for 11-13 minutes, until edges are set and centers still look soft.
07 -
Let the cookies cool on the pan for 8-10 minutes, then move them to a rack. Serve slightly warm for the softest mochi center.