Cream butter with mixer for about 1 minute until smooth. Add in granulated and light brown sugar. Beat with the mixer on high speed for 3 minutes until light & fluffy.
Add the egg, vanilla, and ½ cup of the Nutella and mix well on low speed.
In a separate small bowl, whisk together the flour, baking soda, and salt. Add the dry ingredients into wet ingredients, and continue to mix on low speed until combined. Increase the mixer speed to medium and mix just until the dough is smooth. Fold in chocolate chips.
Using a melon scooper, scoop out balls of dough and place on greased cookie sheet. Bake for 6-7 minutes. Transfer to a rack to cool completely. Once cooled, take a cookie and spread generously Nutella. Top with another cookie. Continue to make cookie "sandwiches" out of the remaining cookies with the Nutella.
Nutrition Information
Serving size: 2 cookies
Recipe by 2 Sisters 2 Cities at https://www.2sisters2cities.com/2012/04/nans-nutella-cookies/