Preheat the oven to 350 degrees F.
Drain sweet potatoes of their juice. Place sweet potatoes in an 11-cup food processor. Add the rest of the ingredients, except heavy cream, to food processor. Process mixture until smooth. Using a pastry brush, brush heavy cream over the surface of the frozen pie shell. Spoon sweet potato mixture into pie crust smoothing the top over. (Stop here and look below if using pecan topping.) Place on baking sheet and bake in the middle lower third of the oven for 45 minutes. Remove from oven and allow to cool in the refrigerator for several hours or overnight.
In a medium saucepan place all ingredients over medium heat. Bring to a boil, reduce heat and cook, stirring constantly for 8 minutes. Remove from heat, allow to cool slightly but still warm and pliable.
Add sweet potato filling to piecrust, spreading evenly over bottom of crust. Next, carefully spoon pecan mixture over sweet potato filling. Place on a sheet pan in the lower third of a 350 degree F oven and bake for 45 minutes to 1 hour. Remove from oven allow to cool in the refrigerator for several hours or overnight.