Chocolate Chip Skillet Brookie

butter (, melted)

brown sugar

white sugar ((or natural granulated sweetener to cut down on calories))

unsweetened cocoa powder

large egg

pure vanilla extract

salt

all-purpose flour ((or plain flour))

butter (, softened)

light brown sugar

granulated sugar ((or natural granulated sweetener))

large egg

pure vanilla extract

all-purpose flour ((or plain four))

baking soda

salt

dark/semi-sweet chocolate chips (, divided (I use Lily's Baking Chips))