Preheat oven to 375°F and grease a 9x13 inch baking dish.
In a small bowl, combine flour, baking soda, and salt.
In a large mixing bowl, beat butter, sugar, brown sugar, and vanilla until creamy.
Add eggs one at a time, beating well after each addition.
Gradually mix in the flour mixture, then fold in chocolate chips.
Spread half of the cookie dough evenly into the prepared pan.
Bake for 8 to 10 minutes until partially baked, then remove from oven.
Meanwhile, melt caramels and evaporated milk in a double boiler until smooth.
Stir in peanut butter until fully melted and combined.
Spread the caramel mixture over the partially baked cookie dough.
Drop spoonfuls of the remaining cookie dough over the caramel layer.
Bake for another 15 to 20 minutes until the top is light golden brown.
Remove from oven and allow to cool completely before cutting and serving.