Preheat oven to 350 degrees and line 2 cookie sheets with parchment paper
Using a large bowl, beat together the butter and sugar until light and fluffy
Beat in the egg, vanilla, and coffee powder until combined
In a medium bowl, whisk together the flour, cocoa powder, and kosher salt
Gradually beat in the dry ingredients until combined
Using a small ice cream scooper, scoop the cookie dough into your hand and roll into a ball
Pour the 1 C of sugar into another bowl
Roll the dough ball into the sugar
Place onto the cookie sheet
Using your thumb, make an indent into the center of the dough
Place into the oven and bake for 8 minutes
Allow cooling completely