½ cup (113 grams) unsalted butter, softened½ cup (110 grams) firmly packed light brown sugar¼ cup (50 grams) granulated sugar1 tablespoon (6 grams) instant espresso powder¼ cup (85 grams) plus 1½ tablespoons (32 grams) maple syrup, divided1 large egg (50 grams), room temperature1 teaspoon vanilla extract1½ cups (188 grams) all-purpose flour½ teaspoon baking soda½ teaspoon plus ⅛ teaspoon kosher salt, divided1½ cups (180 grams) confectioners’ sugar2 tablespoons (30 grams) waterGarnish: flaked sea salt
In the bowl of a stand mixer fitted with the paddle attachment, beat butter, brown sugar, granulated sugar, and espresso powder at medium speed until light and fluffy, 2 to 3 minutes, stopping to scrape sides of bowl. Beat in ¼ cup (85 grams) maple syrup until combined. Beat in egg and vanilla until combined, stopping to scrape sides of bowl.
In a medium bowl, whisk together flour, baking soda, and ½ teaspoon kosher salt. With mixer on low speed, gradually add flour mixture to butter mixture, beating until just combined and no dry streaks remain. (Dough will be soft.)
Line rimmed baking sheets with parchment paper. Using a 1½-tablespoon spring-loaded scoop, scoop dough (about 25 grams each), and place at least 2½ inches apart on prepared pans. Cover and refrigerate for 30 minutes to 1 hour.
Preheat oven to 350°F (180°C).
Bake until edges are set and light golden brown and tops look dry, 15 to 18 minutes. Let cool on pans for 10 minutes. Remove from pans, and let cool completely on a wire rack.
In another medium bowl, whisk together confectioners’ sugar, 2 tablespoons (30 grams) water, remaining 1½ tablespoons (32 grams) maple syrup, and remaining ⅛ teaspoon kosher salt. Dip cookies into glaze as desired. Garnish with sea salt, if desired. Store in an airtight container for up to 1 week.