Line a baking tray with parchment paper. Scoop 1-tablespoon balls of Nutella onto prepared baking sheet and put them in the freezer for about an hour.
Pre-heat the oven to 190C/170C Fan and line 2 baking tins with baking parchment. Then beat the butter and sugar until light and fluffy.
Add the egg and vanilla and beat until combined, then add flour, baking soda, cornflour and salt.
Fold in the chocolate chips until fully combined. Using an ice cream scoop, scoop out the ball of cookie dough and flatten.
Add a ball of nutella to the middle of the cookie dough then roll the cookie dough ensuring the nutella was fully covered.
Add the balls to the tray making sure to leave enough space for them to spread. Bake in the oven for 12 minutes.