Old School Cafeteria Peanut Butter Candy

1 pound graham crackers
2 pounds peanut butter
1 pound powdered sugar
2 tablespoons butter, softened

Break crackers into large pieces in bowl. Add remaining ingredients. Beat 5 minutes. Form into 3-inch diameter logs. Roll in chopped nuts or powdered sugar. Chill.

Slice into 3/8-inch slices.