PREP: Position a rack in the center of the oven and preheat the oven to 350ºF. Cut a circle of parchment that fits in the bottom of a 10-inch cast-iron skillet. Spray the entire skillet iwth with cooking spray (or rub with butter,) place the parchment inside the skillet; set aside for now.

DOUGH: In a large bowl, combine the butter and both sugars using a whisk until smooth; about 1 minute. Then add the egg, yolk, vanilla, and kosher salt and continue to whisk for 30 seconds. Allow the mixture to rest, untouched for 2 minutes. Then whisk for another minute. You could also do this in an electric mixer, stopping the mixer in between. Then, add the flour, baking powder, and baking soda. Fold the mixture halfway, add most of the chips and continue to fold until *JUST* combined.

BAKE: Dump the cookie dough in the prepared skillet and spread it out into an even layer with fingertips or a silicone spatula. Top with remaining chocolate chips. Bake for 27-35 minutes. Tent loosely with foil after the first 20 minutes if the cookie dough has reached your ideal level of browning. Baking for 27 minutes will yield a gooey slightly uncooked cookie center. Baking for 35 minutes will produce a more set + firm cookie. Remove, let cool for 10-15 minutes before serving. Top with ice cream if you’d like!