Chocolate Chip Skillet Brookie - Cookie + Brownie Skillet Cookie

Ingredients

• 1 box brownie mix - 19 ounce size ((I use Ghirardelli Triple Fudge))
• ingredients listed on brownie mix
• 8 tablespoons unsalted butter, room temperature
• 1/2 cup granulated sugar
• 1/4 cup + 2 tablespoons brown sugar
• 1 large egg
• 1/2 tablespoon pure vanilla extract
• 1/2 teaspoon salt
• 1/2 teaspoon baking soda
• 1-3/4 cups all-purpose flour
• 1 cup semi-sweet chocolate chips