Line a 13- by 9-inch pan with foil. Spray lightly with nonstick cooking spray.

Place 5 cups of the Rice Krispies in a large bowl (the largest bowl you have).

Place sugar and corn syrup in a large non-stick saucepan. Bring to a boil over medium-high heat. Continue to boil for 1 minute, no more. (Boiling time is important, it guarantees the perfect texture.)

Turn off burner and remove the pan from the heat. Stir in the peanut butter until incorporated. Add mixture to the Rice Krispies, stirring to coat. Add the remaining cup of Rice Krispies 1/4-cup at a time, stirring and checking consistency before adding more. You want to have some candy mixture remaining without rice krispies. I usually have about 1/4 cup of Krispies left at the end (only adding about 5 3/4 cups). You do not want them too dry.

Spread the mixture evenly into prepared pan. Let cool before cutting into squares. (Warm knife in hot water to help cut nice, clean squares.)