Chex Muddy Buddies

9		cups Chex cereal (any variety)
1		package (6 ounces) semisweet chocolate chips (1 cup)
1/2		cup peanut butter
1/4		cup butter or margarine (do not use spread or tub products)
1		teaspoon vanilla
11/2		cups powdered sugar

Measure cereal into large bowl; set aside. Microwave chocolate chips, peanut butter, and butter in 1 quart microwaveable bowl uncovered on High 1 minute; stir. Microwave 30 seconds longer or until mixture can be stirred smooth. Stir in vanilla. Pour chocolate mixture over cereal in bowl; stirring until evenly coated. Pour in large plastic food-storage bag; add powdered sugar. Seal bag; shake until well coated. Spread on waxed paper to cool. Store in airtight container in refrigerator.