1-Prep the Nutella: Freeze 1.5-teaspoon dollops of Nutella on a parchment-lined tray for at least 20 minutes until solid.

2-Cream the butter and sugars: Beat room-temperature butter with both sugars until pale and creamy, about 3 minutes.

3-Add eggs and vanilla: Beat in eggs one at a time, then vanilla, until smooth; avoid overmixing.

4-Mix the dry ingredients: Whisk flour, baking soda, and salt; gradually add to wet mixture, then fold in chocolate chips.

5-Assemble the stuffed cookies: Flatten dough disc, place frozen Nutella in center, cover with another disc, seal edges, and roll into a ball.

6-Chill the cookie balls: Refrigerate stuffed dough balls for 15–30 minutes to firm up.

7-Bake: Preheat oven to 350°F; bake on parchment-lined sheets for 10–12 minutes until edges are golden and centers soft.

8-Finish with flaky salt: Sprinkle with flaky sea salt immediately, rest on baking sheet 5 minutes, then transfer to wire rack.