Preheat the oven to 375 degrees. Line a baking sheet with parchment paper.
In a large mixing bowl, whisk together 5 of the eggs, the sugar, cocoa powder, olive oil, and vanilla.
In a separate bowl, whisk together the flour, baking powder, and salt.
Add the dry ingredients into the wet ingredients and mix with a spatula, your hands, or an electric mixer until a dough forms.
Take a golf ball sized piece of dough and roll it into a ball. Press it down with your palm, then gently flatten the edges with your fingers to form a disc.
Add about 1 teaspoon of Nutella to the center, then fold the dough around it and seal well.
Place the cookies about 2 inches apart on the prepared baking sheet.
Beat the remaining egg in a small bowl and brush each cookie with the egg wash. Top each cookie with 3 candy eggs.
