Better Than Anything Bars

Ingredients:

1 box chocolate cake mix,

 1/2 cup unsalted butter, melted, 

1 can (14 oz) sweetened condensed milk,

 1 jar (12 oz) caramel sauce, 

1 container (8 oz) whipped topping

 thawed, 1/2 cup chocolate chips,

 1/2 cup peanut butter chips.