In a large saucepan over medium-high heat, combine the sugar and light corn syrup.  Bring just to a boil. Remove from heat. 

Add and stir to combine peanut butter.

Add and stir until well combined with Special K cereal.

Pat the mixture into an even layer in a 9x13 glass baking dish and set aside to cool to room temperature. 

In a double boiler, melt together:

One package of butterscotch chips and one package of semisweet chocolate chips. 

Cool slightly and spread evenly over the cereal mixture.