1 cup granulated white sugar
1 cup Karo white syrup
1 cup peanut butter
3 1/2 cups Rice Krispies
3 1/2 cups Chocolate (or plain) Cheerios
1 tsp. vanilla (optional)

Combine sugar and syrup in a saucepan. Cook until sugar dissolved (almost boiling) but do NOT boil. Stir in peanut butter (do NOT whip).

Mix in cereals. Using a large heat proof spatula, transfer the mixture onto a greased cookie sheet or silicone baking sheet. Cool and cut into bars.