Preheat oven to 350°F degrees (or 340°F if you are using a convection oven) and line a baking sheet with parchment paper, set aside.

In a mixing bowl of a stand mixer fitted with a paddle attachment, whisk together the egg and ¾ cup of Nutella until well combined. Add flour and coffee powder until well incorporated. Cover bowl with plastic wrap and let rest in fridge for not more than 15 minutes (otherwise the dough will crack when forming the balls).

Using a tablespoon, scoop out the dough and form balls placing them about 2 inches apart.

If you want to pipe out the cookies, add about ¼ cup or less milk. Add a little milk at a time until you get the consistency you need for piping. Mix the batter. Fill a pastry bag and squeeze the dough out forming a circle about an inch in diameter. (one full turn and a half should suffice) Bake for about 13 minutes. Remove from oven and let cook down to firm up a bit. Store in an air tight container or freeze.