In a mixing bowl, add Nutella and egg and mix until smooth.
Add brown sugar and mix again.
Add flour, baking powder and mix until crumbly.
Add roughly chopped chocolate and use your hands to combine everything together.
Scoop out small portions of the dough and roll them into little balls. Place them on a cookie tray, lined with parchment paper.
Refrigerate the tray for 15 minutes.
Bake at 350 degrees F or 8-10 minutes or until the edges have set but the centers are still slightly soft and jiggly.
Remove from oven and before the cookies have a chance to cool completely, push a few more chocolate chips on top of each cookie. Enjoy.
Video
Notes
Don't replace brown sugar with granulated sugar. I tried it and it didn't work. The texture of the cookies got messed up.
Make sure to line baking tray with parchment paper to prevent cookies from sticking to the pan.
You must chill the cookie dough balls to prevent the cookies from spreading during baking.
Leftovers can be stored in a sealed container in the refrigerator for up to 5 days or at room temperature for up to 3 days. Reheat in the microwave for 10 seconds to make them ooey gooey and soft again.