• Lightly grease a 9x13 pan. Pour 5 cups Rice Krispies cereal into a large mixing bowl and set aside.
• In a medium-sized saucepan over medium heat, combine 1 cup light corn syrup and 1 cup granulated sugar. Heat until the sugar has completely dissolved and the mixture is near boiling, but do not allow it to boil. Aim for a temperature of about 199-200 degrees Fahrenheit.
• Remove the saucepan from the heat and stir in 1 cup creamy peanut butter, 1 teaspoon vanilla extract, and 1/2 teaspoon salt until the mixture is smooth.
• Pour the peanut butter and sugar mixture over the cereal. Gently fold the cereal into the mixture until everything is evenly coated.
• Fold 3/4 cup Heath toffee bits into the mixture. Be sure to add the toffee bits after the cereal is coated with the peanut butter mixture to avoid melting the bits, which helps retain their crunch.
• Spread the mixture evenly across the bottom of the greased pan, pressing gently to ensure it is level.

For the topping:

• In a microwave-safe bowl, combine 1 cup chocolate chips and 1 cup butterscotch chips. Microwave on high in 30-second intervals, stirring in between, until the chips are melted and smooth.
• Spread the melted chocolate and butterscotch over the top of the cereal layer in the pan.
• Sprinkle the remaining 1/4 cup of Heath toffee bits over the melted topping.
• Allow the Scotcharoos to set until the topping solidifies. Cut into squares and serve.