Line 8-inch square pan with foil, extending foil over edges of pan.
In medium bowl, place peanut butter chips.
In second medium bowl, place chocolate chips.
In heavy 3-quart saucepan, combine sugar, marshmallow creme, evaporated milk and butter.
Cook over medium heat, stirring constantly, until mixture comes to a boil; boil 5 minutes, stirring constantly.
Remove from heat; stir in vanilla.
Immediately stir half of the hot mixture (1 1/2 cups) into peanut butter chips until chips are completely melted; quickly spread into prepared pan.
Stir remaining hot mixture into chocolate chips until chips are completely melted.
Quickly spread over top of peanut butter layer.
Coo1 to room temperature; refrigerate until firm.
Use foil to lift fudge out of pan; peel off foil.
Cut into 1-inch squares.
Store in tightly covered container at room temperature.