Line a 9×13 pan (or quarter baking sheet like I used) with parchment paper. Make space in your freezer for the pan. You will be putting it in the freezer and pulling it back out several times.
Bottom layer: Melt 1 cup chocolate chips + 1/4 cup peanut butter in the microwave for about 1 minute 30 seconds. Stir until smooth, then spread on the bottom of the pan. Put pan in freezer.
Nougat layer: Put butter, sugar and 1/4 cup evaporated milk in a small saucepan. Begin heating on medium heat, stirring occasionally as the butter melts and the mixture combines. Measure out 1/4 cup peanut butter and set aside. Continue heating mixture. When it comes to a boil, set timer for 6 minutes. After 6 minutes, remove from heat and stir in 1/4 cup peanut butter, the marshmallow cream and the vanilla. Stir until smooth. Take pan out of freezer and pour nougat on top of chilled chocolate. Smooth over chocolate until layer is even. Return to freezer.
Caramel layer: Melt caramels + 1/4 cup evaporated milk in the microwave for 1 minute, adding 30 second increments as needed until caramels melt and mixture is combined.
Take pan out of freezer. Measure out 1 1/2 cups salted peanuts and pour evenly over the top. Use clean hands to gently press peanuts into nougat. Pour caramel mixture over the top of the peanuts. Return pan to freezer.
Top layer: Melt 1 cup chocolate chips + 1/4 cup peanut butter in the microwave for about 1 minute 30 seconds. Stir until smooth, then spread on top of the caramel, until even.
Return pan to freezer for about 20 minutes. Cut into squares while bars are still cold. (this makes cutting nice and even!)
Bars need to be stored in the fridge, but will still maintain their shape even when left out for a couple hours. They do get soft though, which is why I prefer to store them in the fridge.