Preheat the oven to 350°F and line a baking sheet with parchment paper.
In a large bowl, mix the chocolate hazelnut spread with the egg until smooth. Add the flour, and mix well until combined.
Divide the dough into 1 ½ tablespoon-sized balls using a spring-loaded scoop. Sprinkle the chopped hazelnut on top.
Bake in the preheated oven for 8-12 minutes or until cookie edges have set and the cookie tops are slightly cracked. Cool on the baking sheet for 5 minutes, then transfer to wire racks to cool completely.
Notes
Storage: Store the cookies in an airtight container for up to one week.Make ahead Instructions: You can also make the dough a day ahead of time and store covered in the fridge. Make sure that your cookies are fully cooled before storing.Tip: You will know the cookies are cooked because they will lose their shine. Remember that the cookies will continue to cook once they are removed from the oven, so let them cool completely.