Caramel mixture: brown sugar, butter and Karo syrup. Put in saucepan over medium heat. Bring to a rolling boil for 2 minutes. Pour over cereal mixture (rice chex, corn chex, pretzels, and cashews) and coat evenly. Bake at 250 degrees for 30 minutes, stirring every 10 minutes. Cool on waxed paper that has been sprayed with Pam. Store in air-tight container or plastic bag. This is absolutely delicious!!!