Puppy Chow Snack

1 cup semisweet chocolate chips
1/2 cup peanut butter
1/4 cup butter or margarine
1 tsp. vanilla
2 cups powdered sugar
9 cups Crispix or Chex cereal

Into large bowl, measure cereal; set aside. In 1-quart saucepan, heat chocolate chips, peanut butter and butter over low heat, stirring frequently, until melted. Remove from heat; stir in vanilla.
Pour mixture over cereal, stirring until evenly coated. Pour into 2-gallon resealable food-storage plastic bag or large brown paper grocery bag. Add powdered sugar. Seal bag; shake until well coated.
Spread on waxed paper to cool. Store in airtight container in refrigerator.