Line a baking sheet or tray with parchment or waxed paper; set aside.
In a shallow dish combine cornflakes, peanuts, and chocolate pieces. Roll scoops of frozen yogurt, one at a time, in cereal mixture, forming a ball and pressing cereal mixture onto sides. Place coated scoops on prepared baking sheet; cover with plastic wrap.
Freeze until firm or up to 6 hours. To serve, place coated scoops in dessert dishes. Makes 8 servings.