Weigh out the ingredients
You'll need chocolate, flour, brown sugar, granulated sugar, eggs, cocoa powder, oil, Nutella, salt, baking powder, and vanilla extract.
Mix dry ingredients
In a small bowl, combine the flour, cocoa powder, baking powder, and salt. Set aside.
In a medium heat proof bowl add the chocolate and oil, and place over a small saucepan with simmering water. Stir occasionally until completely melted. Remove from heat and set aside.
Heat chocolate & oil
In the bowl of a stand mixer fitted with the whisk attachment, whip the granulated sugar, brown sugar, eggs, and one teaspoon vanilla on high speed for 2-3 minutes until light and pale in color.
Whisk wet ingredients & sugar
While mixing on low speed, drizzle in the melted chocolate mixture and mix until fully combined.
Add melted chocolate
Lastly add in the flour mixture and mix until just combined. The batter should be soft, but able to hold a ball shape when scooped.
Add dry ingredients
Immediately scoop the batter onto the prepared baking sheets about two inches apart. Inject each cookie dough ball with Nutella.
Scoop & inject
Bake the cookies for about 8-10 minutes until they are crackly, shiny, and appear set. Allow to cool completely on baking sheet.
Bake & cool