Muddy Buddies

9 cups Chex cereal (in Canada I use Crispix)
3/4 cup of semisweet choco chips
1/2 cup peanut butter
1/4 cup butter
1/2 tsp vanilla
1 1/2 cups powdered sugar

Measure cereal into large bowl; set aside. Microwave chocolate chips, peanut butter and butter in a medium bowl 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. Put powdered sugar in a large plastic bag. Shake powder around bag, then add chocolate mixture into bag and shake until each piece is well coated with powdered sugar. Cool on waxed paper.