Place wax paper over a cookie. For large cookies, spoon 2 teaspoon of Nutella per cookie. Make 16 piles of 2 teaspoon of Nutella. For smaller cookies only do 1 tsp. Freeze for at least an hour.
Mix flour, baking soda, corn starch, and salt in a mixing bowl.
Using a mixer, beat butter, sugar, and brown sugar. Beat until the butter is light and fluffy. Add in vanilla and eggs. Mix until combined. Scrape the bowl to make sure all the butter is mixed in.
Slowly add in the dry ingredients until combined. Add in chocolate chips and mini chocolate chips. Mix until combined.
Chill dough for 30 minutes. Prep 2 cookie sheets with parchment paper. Use a large 3 oz cookie scoop to make large cookies. Scoop all the dough. Flatten each cookie one a time into a disc. Place Nutella in the middle of the dough and wrap the dough around the Nutella. Roll into a ball. Keep the Nutella in the freezer while you work because it melts very fast.
Chill for another 20 minutes. Chilling prevents the cookies from spreading in the oven. Preheat oven to 350°F. Place 6 cookies per cookie sheet.
Bake for 13-15 minutes. Bake until edges of cookies are golden brown. Use a spoon on the edges to make the cookie circular. Top with extra chocolate chips and tiny little pools of Nutella, Place on top while the cookies are warm for the chocolate to melt. Let cookies sit for 4 minutes before transferring to a cooling rack.