In a mixing bowl whisk together flour, baking powder, salt and keep aside.
In another bowl beat together cocoa powder, sugar and oil in a bowl till it form a black sticky mass. You can do this by hand mixer but I just did it manually with a balloon whisk.
Add one egg at a time and beat well to incorporate after each addition.
Add instant espresso powder, vanilla essence and mix well.
Add the flour mixture and mix well with a spatula until incorporated. Do not overdo it. The dough will be super sticky.
Cover the bowl with a lid and chill it overnight or for at least 4 hours in the Refrigerator. (I left it overnight).
When you are ready to bake, take it out of the fridge and make small balls from the dough and keep it ready. No need to thaw the dough to room temperature.
Take the powdered sugar in a bowl and roll the balls in the sugar ensuring they are well coated and fully covered with the powdered sugar.
Preheat the oven at 180 Deg C / 350 Deg F.
Place the balls on a baking tray leaving 2 inch gap between them and bake for 15 minutes.
Take out of the tray and let it cool on a wire rack for 5 minutes.
Store in an airtight jar.