Preheat oven to 375 degrees.
In a 12 inch non stick, oven safe skillet, melt butter over medium heat.
Remove from heat and stir in sugar, salt and vanilla.
Once sugar and butter is well combined, stir in egg and egg yolk.
Add flour and baking soda and mix until all flour in incorporated.
Stir in chocolate chips and spread cookie dough evenly in the skillet.
Bake for 15-18 minutes on middle rack, until edges are a light golden brown.
Do not over bake as cookie will continue to cook as it cools.