To caramelize the white chocolate, heat oven to 250℉. Spread 1 cup white chocolate chips evenly over a baking dish. Heat the chips in the oven, stirring every 10 minutes, until browned and fragrant, about 30- 40 minutes.
Heat the butter, corn syrup, cream, carameilzed white chocolate, and remaining white chocolate chips in a medium saucepan over medium heat. Stir mixture until chocolate is completely melted. Add pumpkin, cinnamon, and salt.
Measure cereal into a large bowl. Pour pumpkin ganache over cereal, stirring until evenly coated. Pour into 2-gallon resealable food-storage plastic bag.
Add powdered sugar. Seal bag; shake until well coated. Spread on waxed paper to cool. Store in airtight container in refrigerator.
Recipe by Allons-Eat! at https://www.allonseat.com/pumpkin-pie-muddy-buddies/