Heat oven to 450°F. Remove pie crust from pouch; unfold on ungreased 12-inch pizza pan. Press out fold lines. Decoratively flute edge of crust. With fork, prick holes over entire surface of crust. Bake at 450°F. for 9 to 11 minutes or until golden brown. Cool crust while preparing pudding mixture.
Meanwhile, in small saucepan, combine pudding mix and milk; mix with wire whisk. Cook over medium-high heat until bubbly and thickened, stirring constantly with wire whisk. Remove from heat. Stir in vanilla chips until melted. Cool 5 minutes.
Spoon pudding mixture onto cooled baked crust; spread evenly to within 1/2 inch of edges. Reserve 1 cherry for garnish; spread remaining pie filling over pudding mixture to within 1 inch of edge of pudding. Spoon whipped topping onto center of pizza. Garnish with reserved cherry. Store in refrigerator.