• Preheat an oven to 350 F.

Brown the butter:

• Melt the butter in a 10 to 11-inch cast iron skillet over medium low heat. Cook, swirling the butter occasionally, until golden brown with a nutty aroma. Pour the brown butter into a heat-safe mixing bowl and cool for 5-10 minutes.
• Cook, swirling the butter occasionally, until golden brown with a nutty aroma.
• Pour the brown butter into a heat-safe mixing bowl and cool for 5-10 minutes.

Mix in sugar and eggs:

• Whisk both sugars into the butter until very smooth, about 2 minutes of whisking.
• Whisk in the egg, egg yolk, and vanilla until smooth.

Mix the dry ingredients:

• In a separate bowl, whisk together the flour, baking soda, and kosher salt.

Fold in the dry ingredients:

• Use a rubber spatula to fold the dry ingredients and chopped chocolate into the wet until mixed and no streaks of flour remain.

Prep cookie for baking:

• Press half the cookie dough into the skillet you used to brown the butter. Add dots of chilled Nutella over the top. Press the other half of the cookie dough into the skillet to cover the dots of Nutella.
• Bake for 22-24 minutes, until slightly golden brown and puffed. Remove the skillet from the oven and top with flaky sea salt. Serve while still warm, topped with ice cream.

Notes:

• If using a smaller skillet, bake a little bit longer. I don’t recommend using a skillet larger than 11″ unless you increase the recipe ingredient quantities by 25%.