Freeze Nutella by scooping tablespoon-sized portions onto a parchment-lined baking sheet and freeze for at least 2 hours.

Prepare dough by beating together butter, brown sugar, and granulated sugar until light and fluffy.

Add the whole egg, egg yolk, and vanilla extract to the mixture and beat until smooth.

In a separate bowl, whisk together flour, baking soda, and salt, then gradually mix into wet ingredients.

Fold in semi-sweet chocolate chips until evenly distributed.

Chill the dough covered for at least 1 hour.

Shape cookies by taking chilled dough, placing a frozen Nutella disc in the center, and folding the dough around it.

Bake at 350°F (175°C) for 11-13 minutes until edges are set but centers are underdone.

Cool cookies on the baking sheet for 5 minutes before transferring to a wire rack.