Chocolate Chip Nutella Cookie

1. Preheat the oven to 375 F.
2. Place 9 tablespoons of butter in a small saucepan and melt it over medium heat. Cook the butter, stirring constantly, until it’s dark golden brown and the bubbling has subsided, about 4-5 minutes.
3. Pour the brown butter in a medium heat-safe bowl. Add the remaining 3 tablespoons of butter and stir until incorporated.
4. Add the brown sugar, granulated sugar, vanilla, and salt and whisk until smooth. Whisk in the egg and egg yolk.
5. Let the butter mixture rest for 3 minutes, then whisk for 30 seconds. Repeat this two additional times. The resulting dough should be thick, smooth, and shiny.
6. Add the flour and baking soda and stir until combined. Stir in the chocolate chips.
7. Place the Nutella in a microwave safe bowl and heat briefly in the microwave so that it is slightly melted and easy to spread.
8. Press half of the cookie dough into a 10 or 12 inch cast iron skillet.
9. Spread the Nutella onto the cookie dough. Spread the remaining cookie dough on top of the Nutella layer.
10. Bake cookie for 20-25 minutes, until the cookie is golden brown and the edges are set.
11. Let the cookie cool in the pan for 30 minutes before serving.