Line 2 baking sheets with parchment, and heat oven to 350°F. Set oven racks to upper-middle and lower-middle positions.
In a medium bowl, whisk the flour, cocoa, espresso powder, baking powder, baking soda, and salt together; set aside.
1½ cups all-purpose flour, ½ cup unsweetened cocoa powder, ½ teaspoon espresso powder, ¼ teaspoon baking powder, ¼ teaspoon baking soda, ½ teaspoon kosher salt
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugar on medium-high speed until light and fluffy, about 2-3 minutes. Add egg and vanilla and mix just until incorporated. Add all flour mixture and mix on lowest speed just until no flour shows.
8 tablespoons unsalted butter, 1 cup granulated sugar, 1 large egg, 1½ teaspoons pure vanilla extract
Roll dough into 1-inch balls, then roll the balls into the Turbinado sugar. Set balls 2-inches apart on the prepared baking sheets.
Turbinado or Demerara sugar
Using a greased, rounded ½-teaspoon measuring spoon, make an indentation in the center of each ball of dough.
Bake at 350°F until set about 10-12 minutes, switching and rotating sheets halfway through baking.