In a medium bowl, whisk together flour, baking powder, espresso powder and salt; set aside.

In a large bowl, using a hand mixer beat together sugar, cocoa powder, vegetable oil and vanilla until it resembles wet sand.

In a large bowl, using a hand mixer beat together sugar, cocoa powder, vegetable oil and vanilla until it resembles wet sand.

Gradually add the dry ingredients into the wet ingredients a 1/2 cup at a time just until combined; do not over mix.

Cover the dough with plastic wrap and refrigerate for at least 4 hours or overnight.

Preheat oven to 350 degrees. Line baking sheets with parchment paper; set aside.

Pour confectioner's sugar into a bowl; set aside.

Remove the dough from the refrigerator. Scoop out rounded teaspoonfuls of dough and roll into 1-inch balls. Roll each dough ball into confectioners’ sugar and place on cookie sheets.

Bake for 10-12 minutes. Allow to cool a minute or two on the sheets before transferring to a wire rack to cool completely.