Combine shredded wheat biscuits, toasted oat cereal, pretzels, and peanuts in a large buttered roasting pan.

Butter the sides of 2-quart saucepan. In the pan combine sugar, butter or margarine, and corn syrup. Cook over medium heat to boiling, stirring constantly with a wooden spoon to dissolve sugar. Cook, stirring frequently, till thermometer registers 280F, soft-crack stage. This should take about 10 minutes. Remove saucepan from heat and stir in vanilla.

Immediately pour syrup mixture over cereal mixture. Stir gently to coat cereal. Bake in a 350F oven about 20 minutes or till golden brown, stirring once.

Transfer cereal mixture onto a large piece of foil. Cool. Break up cereal mixture into small clusters. Store tightly covered. Makes 12 cups.