Instructions

• Preheat oven to 350°F (175°C). Line a 9" cast-iron skillet or 9" pie dish with parchment paper and set aside.
• In a large bowl, combine the softened butter, light brown sugar, granulated sugar, and vanilla extract. Beat or whisk until the mixture is light and creamy.
• Whisk in the egg until fully incorporated.
• Add the flour, baking soda, and salt. Stir until the dry ingredients are just combined into the wet mixture; do not overmix.
• Fold in half of the chocolate chips, reserving the rest for the top.
• Divide the cookie dough into two equal portions. Spoon or press one half of the dough evenly into the prepared skillet to form a base.
• Place the 1/2 cup Nutella in a microwave-safe bowl and microwave for about 30 seconds, then stir until it becomes thinner and spreadable.
• Spread the melted Nutella over the cookie dough base, leaving about a 1-inch border around the edge.
• Top with the remaining half of the cookie dough, smoothing it gently with the back of a spoon or your fingers to cover the Nutella. Sprinkle the reserved chocolate chips over the top.
• Bake in the preheated oven 25–30 minutes for a gooey cookie. For a firmer, fully set cookie, bake 30 minutes uncovered, then tent with aluminum foil and bake an additional 10 minutes (about 40 minutes total).
• Remove from oven and let cool in the skillet for about 10 minutes before slicing and serving.