Prepare 2 baking sheets by lining with parchment paper or silicone mats.
Pour 2 tablespoons boiling water over 1 tablespoon instant espresso. Stir until dissolved. Set aside.
In a medium bowl, whisk together the flour, baking soda and baking powder. Set aside.
Using a stand mixer with the paddle attachment, begin creaming the butter and granulated sugar until light and fluffy (2 - 4 minutes on medium speed). Scrape the bowl as needed. Note: a hand mixer may also be used
Add the egg yolk and espresso/water mixture to the bowl. Mix on medium speed until well combined. Scrape the bowl as needed.
Add the flour mixture and mix on low speed until combined.
Sugar Coating
Combine 1 cup of granulated sugar with 1 tablespoon instant espresso powder. Rub the mixture together with fingertips to work the espresso into the sugar.
Scoop approximately 2 tablespoons of cookie dough and roll into a ball. Roll in the sugar/espresso mixture until well coated.
Bake and Cool
Place the cookies onto the prepared baking sheets. Leave approximately 2 inches of space between each cookie. Note: the cookies will spread to almost twice the size.
Bake cookies for 10 - 12 minutes, or until tops and edges of cookies are browning.
Let cookies cool on the baking sheets for 5 to 10 minutes, then transfer them to a wire rack to cool completely.