Prepare 9" baked pie shell as directed on package. (For a firmer baked pie shell, freeze about 30 minutes before filling.) Quickly pack scoops of ice cream, alternating flavors, in pie shell. Freeze until firm.
Heat oven to 500 degrees. Beat egg whites and cream of tartar until foamy. Beat in sugar, 1 tablespoon at a time; continue beating until stiff and glossy. Do not underbeat. Beat in vanilla.
Working quickly, heap meringue onto ice cream; spread over ice cream, carefully sealing to edge of crust. Bake 3 to 5 minutes or until top is light brown. Serve immediately.
