Crush the cereal pieces slightly and mix with the cranberries and pistachios.
Combine the butter, sugar and honey in a small sauce pan. Bring to a boil and let it simmer for about 3 minutes.
Spray an 8 x 8 glass casserole dish with cooking spray.
Quickly pour the sugar syrup into the bowl with the cereal. Mix well, then press into the casserole dish. Use waxed paper to press down and flatten the mixture.