1. Butter 9-inch pie plate.
2. Place 1/2 cup chocolate syrup and chocolate chips in medium microwave-safe bowl. Microwave at MEDIUM (50%) 45 seconds or until hot; stir until smooth. Reserve 1/4 cup chocolate syrup mixture; set aside. Add cereal to remaining chocolate syrup mixture, stirring until well coated; cool slightly.
3. Press cereal mixture, using back of spoon, evenly on bottom and up sides of prepared pie plate to form crust. Place in freezer 15 to 20 minutes or until crust is firm. Spread half of vanilla ice cream into crust; spoon reserved 1/4 cup chocolate syrup mixture over layer. Spread half of chocolate ice cream over sauce.
4. Top with alternating scoops of vanilla and chocolate ice cream. Cover; return to freezer until serving time. Drizzle with additional syrup just before serving. Makes 8 servings.