Grease a 9x13" pan and set aside.
In a large saucepan, add the brown sugar, corn syrup and caramel topping.
Turn the stovetop on low heat and stir until the brown sugar is dissolved. DO NOT let the mixture come to a boil. Once the sugar is dissolved, remove the saucepan from the heat.
Stir in the peanut butter, vanilla and salt.
Stir in the crispy rice cereal, chopped peanut butter cups and toffee bits.
Pour into the prepared pan and pat into place.
In a microwave safe bowl, add the chocolate and butterscotch chips.
Cook on high in 20 second intervals, stirring after each interval until the chocolate is smooth.
Spread over the bars then sprinkle with additional chopped peanut butter cups and toffee bits.
Let cool before cutting into bars.