In a mixing bowl combine the flour, salt, espresso powder, and baking powder. Mix until combined.
In a stand mixer, on medium speed, combine the oil and cocoa powder until mixed thoroughly.
Add the sugar and increase the speed to medium-high. Mix until thoroughly combined. The mixture will look gritty and that is ok. Add the eggs one at a time allowing for complete incorporation before adding the next. Scrape the sides as needed. Then add the vanilla.
Reduce the speed to low and add the flour mixture. Mix until the flour disappears. Pour into the mixing bowl and cover. Refrigerate for at least 4 hours or overnight. The dough is good in the refrigerator for up to 24 hours.
Preheat the oven to 350°F or gas mark 4.
Using the cookie scoop roll the dough into a ball and coat in the powdered sugar. Place on the lined sheet pan. Give a 2 inch space between each cookie. Bake for 12 minutes. The baking time is per pan of cookies. Allow for the cookies to set a few minutes before transferring to a cookie rack. Repeat as many times as necessary until you run out of dough, allowing the sheet pan to cool completely before baking again.
Notes
The dough can be frozen for up to 4 weeks.
Not all of the powdered sugar will be used.
If using the 1 tablespoon scoop double the number of cookies expected.