In a large mixing bowl, combine the melted butter, brown sugar, and granulated sugar. Whisk until smooth and creamy.
Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
In another bowl, whisk together the flour, baking soda, and salt. Gradually incorporate the dry ingredients into the wet mixture until just combined.
Fold in the semi-sweet chocolate chips and optional ingredients like crushed walnuts and shredded coconut for added texture and flavor.
Grease a cast-iron skillet or oven-safe skillet with non-stick spray or a little more melted butter. Pour the cookie dough mixture into the skillet, spreading it evenly.
Bake in the preheated oven for 25-30 minutes or until the edges are golden brown, and the center is still slightly soft.
Allow the skillet to cool for 10 minutes before serving warm with a scoop of vanilla ice cream on top, if desired.
Notes
Serve directly in the skillet for a rustic look. Drizzle some melted chocolate over the top and sprinkle with flaky sea salt before digging in!