mix the flour, baking powder, and salt together, set aside

beat the cocoa powder, sugar, espresso powder if using, and oil together, this will look like a gritty mess

beat in the eggs one at a time

stir in the vanilla

mix the flour into the wet ingredients, mix well

gather the dough in a ball, wrap in plastic wrap, it's going to be a really soft dough so once wrapped place it in a bowl to keep it from spreading, and refrigerate for at least 4-6 hours

to bake, preheat the oven to 350˚

line a baking sheet with foil or parchment paper

roll the dough into small balls and then roll in the powdered sugar, you can use a cookie scoop for this

place on the prepared cookie sheet 1-2 inches apart

bake for 10-12 minutes, or until set

remove from the oven, cool 1-2 minutes on the cookie sheet and then remove to a cooling rack

repeat with the remaining dough