Preheat the oven to 350 degrees.
In a large bowl or the bowl of a stand mixer, cream the butter and brown sugar on medium speed until integrated and fluffy, about one minute. Add the egg and vanilla extract and beat to combine an additional 30 seconds. Scrape the sides of the bowl and add the flour, cocoa powder, baking soda, baking powder, espresso powder, and salt. Stir on low speed until combined, scraping the sides of the bowl as needed.
Line two baking sheets with parchment paper or silicone baking mats and pour the sparkling sugar into a small bowl. Scoop 1-1/2 teaspoon sized (medium cookie scoop) balls of dough and roll them in your hands. Roll the dough balls in the sugar and place on the baking sheet about 2 inches apart. Bake in the preheated oven for about 9-10 minutes or until the tops have cracked. Allow to cool on a cooling rack before enjoying.