Preheat oven to 350°F/180°C, line a baking sheet with parchment paper. In a bowl, stir together the flour, espresso powder, baking soda and salt, set aside
Using a medium cookie scoop (1 ½ inch scoop or #40), drop dough onto the prepared cookie sheets 2 inches apart. onto the prepared cookie sheets 2 inches apart.
Bake in the preheated oven for 7-9 minutes, until cookies have spread and are no longer glossy on top; sprinkle with salt if using and allow them to cool 5 minutes before transferring to a wire rack and cooling completely