How to Make It
Preheat oven to 350°F. Whisk together flour, sugar, matcha, baking powder, and salt in a large bowl. Stir in almonds. Add eggs and extracts. Beat with an electric mixer on medium speed until a sticky dough forms, about 2 minutes.
Divide dough in half. Shape each half into an 8-inch-long log on a baking sheet lined with parchment paper. Pat each log to a width of 3 inches. Bake at 350°F until set, about 20 minutes. (Dough will be cracked.)
Remove biscotti logs from oven; cool on pan 5 minutes. Using a wide spatula, carefully transfer biscotti logs to a wire rack; cool 15 minutes. Reduce oven temperature to 300°F.
Place biscotti logs on a cutting board. Cut each diagonally into 12 slices. Return slices to parchment-lined baking sheet. Bake at 300°F 20 minutes, flipping slices after 10 minutes. Cool completely on a wire rack, about 30 minutes.
Place chocolate in a microwavable bowl. Microwave on medium until melted, about 1 minute and 30 seconds, stirring every 30 seconds (be careful not to overheat chocolate so it doesn’t scorch or seize). Stir in espresso granules. Drizzle over biscotti. Let stand until chocolate mixture sets, about 10 minutes.