I got this recipe from a woman, whom I worked with in the 1970's. It is a sweet delicious treat. We like thick bars so I make mine in a 9x9 pan. Serving varies as to which pan is used. Do not let the sugar mixture over cook/boil. The bars will end up being rock hard.
Lightly butter a 13X9 inch pan ( for thicker bars use a 9x9 pan); set aside.
In a large mixing bowl, mix sugar and Karo syrup. Microwave on high for 2-3 minutes, or just until sugar is dissolved. NOTE: Remove immediately after the sugar is dissolved. Do not let BOIL. This will over cook the mixture and cause the bars to be hard as concrete when they set up.
Remove bowl from microwave; add peanut butter to the sugar mixture and stir until smooth.
Stir in the cereal; mix well.
Put the mixture into the prepared pan and pat the mixture firmly into the pan. (Using a lightly buttered piece of waxed paper works great for patting down the mixture in the pan).
In a medium bowl, combine the chocolate and butterscotch chips and microwave for about 2 minutes or until melted; stirring once or twice during the process.
Pour/spread over top of cereal mixture. Refrigerate just long enough to set the chips. Remove, and cut into bars.