Scoop 24-2 teaspoon balls of Nutella onto a baking sheet. Freeze for 1 hour.
In an electric mixer cream together butter and both sugars together until light and fluffy.
Beat in egg and vanilla until the egg is very well incorporated.
Add flour, cornstarch, baking soda and salt. mix until just combined.
Fold in chocolate chips. Scoop 2 Tablespoon balls of dough (medium cookie scoop) onto a baking sheet. Chill the dough for 30 minutes.
Preheat oven to .350º F.
Rewove chilled dough and frozen Nutella from the freezer. Flatten a ball of dough, place a Nutella ball in the center and roll to full enclose. Repeat with remaining dough.
Place balls of dough on baking sheet, about 2 inches apart. Bake for 10-12 minutes until the cookies are golden on the edges and the tops are set and appear dry.
Remove from the oven and allow to cool for a few minutes before removing to a wire rack.