1. Into large bowl, measure cereal; set aside.
2. In 1-quart microwavable bowl, microwave chocolate chips, pumpkin kernel butter and shortening uncovered on High 1 minute. Stir. Microwave about 30 seconds longer or until mixture can be stirred smooth.
(Or melt chocolate chips, pumpkin kernel butter, and shortening on low heat in a double broiler.)
3. Pour mixture over cereal, stirring until evenly coated.
4. Pour into 2-gallon resealable food-storage plastic bag.
5. Add powdered sugar.
6. Seal bag; shake until well coated. Spread on waxed paper to cool. Store in airtight container in refrigerator.