Monkey Munch

9 cups Chex (I usually use 1/2 corn or rice chex and 1/2 wheat chex)
1 cup semisweet chocolate chips
1/2 cup peanut butter
1/4 cup butter
1 teaspoon vanilla
1 1/2 cups powdered sugar

Into large bowl, measure cereal; set aside.In 1-quart microwave bowl, microwave chocolate chips, peanut butter and butter uncovered on high 1 minute; stir. Microwave about 30 seconds longer or until mixture can be stirred smooth. Stir in vanilla. Pour mixture over cereal, stirring until evenly coated. Pour into 2-gallon resealable food-storage plastic bag.Add powdered suguar. Seal bag; shake until well coated. Spread on waxed paper to cool. Store in airtight container in refrigerator.