Place pie crust into a 9-inch pie pan, flute edges. Mix together sweet potatoes, brown sugar, corn syrup, evaporated milk, eggs, salt, cinnamon, nutmeg, cloves and ginger in a large bowl until smooth. Pour mixture into crust. Bake for 15 minutes. Reduce oven temperature to 350°F and bake for an additional 20 minutes.
To make the streusel topping: Mix together brown sugar, flour and cinnamon in a bowl. Cut in butter using a pastry blender or two forks, until blended. Stir in pecans.
Remove pie from oven and sprinkle with streusel. Bake an additional 10 to 15 minutes, or until a knife inserted in the center of the pie comes out clean and streusel is golden brown. Cool pie to room temperature.
Whip together vanilla whipped cream ingredients until stiff peaks form and top pie just before serving.