Start by preheating the oven to 350 degrees Fahrenheit and line 2 cookie sheets with parchment paper to use later.
Then line a quarter sheet pan with parchment paper and using a ½ tablespoon, make 12 small chocolate hazelnut balls. Place them into the freezer while preparing the cookie dough.
To a large mixing bowl add the brownie mix, oil and the egg. Mix everything together with a rubber spatula until combined.
Cover the cookie dough with plastic wrap and place in the refrigerator for 15 minutes.
Remove the cookie dough from the refrigerator and the hazelnut chocolate butter balls from the freezer.
With a 2 oz cookie scoop, scoop the batter, place a chocolate ball into the center of the dough and cover the top with the dough that is spilling over.
Release the cookie onto the baking sheet and repeat until there are 6 cookies evenly spaced on the prepared cookie sheet pan.
Bake the cookies 350 degrees Fahrenheit for 10-12 min until set.
Cool the cookies slightly and dust the tops with powdered sugar.
Continue until all the cookies have been baked.
Serve and enjoy!
Store leftovers in an airtight container (on the counter out of the sun) for up to 3 days or freeze for up to 3 months.
