In a large bowl place the Rice Krispies cereal and the Fruity Pebbles cereal. Stir gently together to mix the cereal together. Set aside.

In a medium sauce pan melt the Karo syrup and sugar and bring to a boil, stirring well. Add the peanut butter and 2 Tbs of butter. Stir until the butter melts and mixture is well combined. Remove from heat and immediately pour mixture over the cereal. Stir together quickly as it will start getting hard. Transfer to a parchment lined jelly roll pan (12 x 7 x 1 inch) or you can spray the pan with cooking spray. Press the mixture evenly into the pan with your hands.

Melt the bag of white chocolate chips following the melting instructions on the bag (usually microwave instructions or double boiler). Add 2 Tbs butter to the melted chips and stir until the butter melts. Spread the white chocolate over the bars. Sprinkle with crushed Fruity Pebbles cereal if desired. Let the bars cool and then slice into squares. These store well and freeze well.