Muddy Buddies or Puppy Chow

Of course if you haven't had this, it is a classic and you must try it.  Crunchy cereal coated in chocolate peanut butter and then covered in sweet powdered sugar.  Excellent and fun for kids to help make.

9 cups Corn Chex, Rice Chex, Wheat Chex or Chocolate Chex cereal (or combination)
1 cup semisweet chocolate chips
1/2 cup peanut butter
1/4 cup butter or margarine
1 teaspoon vanilla
1 1/2 cups powdered sugar

1. Into large bowl, measure cereal; set aside.
2. In 1-quart microwavable 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.
3. Add powdered sugar. Seal bag; shake until well coated. Spread on waxed paper to cool. Store in airtight container in refrigerator.