Preheat oven to 375°F (190°C) and grease a 9×13-inch pan.

Combine flour, baking soda, and salt in a small bowl.

In a large mixing bowl, beat butter, sugars, and vanilla until creamy.

Add eggs one at a time, beating well after each addition.

Gradually mix in the flour mixture. Stir in chocolate chips.

Spread half of the cookie dough into the prepared pan and bake for 8–10 minutes.

While baking, melt caramels with evaporated milk in a double boiler; stir until smooth. Add peanut butter if using.

Pour the caramel mixture over the baked cookie layer.

Drop remaining dough by spoonfuls over the caramel layer.

Bake for 15–20 minutes or until light golden brown.

Cool completely before cutting into squares.