Heat oven to 425°F. Place pie crust in 9-inch glass pie pan as directed on box for One-Crust Filled Pie.
In large bowl, mix filling ingredients until well blended. Pour into crust-lined pan.
Bake 15 minutes. Reduce oven temperature to 350°F; bake 15 minutes. Meanwhile, in small bowl, mix streusel ingredients.
Sprinkle streusel over pumpkin filling. Bake 15 to 20 minutes longer or until knife inserted in center comes out clean. Cool completely, about 1 hour.
Gently fold orange peel into whipped topping. Serve pie with topping. Store in refrigerator.