Preheat the oven to 375°F (190°C). Grease a 9x13-inch baking dish and set aside.
In a small bowl, whisk together the flour, baking soda, and salt.
In a large mixing bowl, beat the butter, granulated sugar, brown sugar, and vanilla until creamy.
Add the eggs one at a time, beating well after each addition.
Gradually mix in the flour mixture until just combined.
Fold in the chocolate chips.
Spread half of the cookie dough evenly into the prepared baking dish.
Bake for 8–10 minutes, then remove from the oven.
While the base bakes, melt the caramels and evaporated milk in a double boiler or microwave, stirring frequently until smooth.
Stir in the peanut butter until fully melted and combined.
Pour the caramel mixture evenly over the baked cookie base.
Drop spoonfuls of the remaining cookie dough over the caramel layer.
Return the pan to the oven and bake for 15–20 minutes, or until the top is light golden brown.
Remove from the oven and allow to cool completely before cutting into bars.