Preheat the oven to 450F. Line a 9-inch pie pan with rolled-out dough and prick all over the bottom, then press a piece of heavy-duty foil directly into the pie shell. Bake for 6 minutes, remove the foil, and then bake for another 4 minutes, or until beginning to brown.
Combine the sweet potatoes and sugar in a large bowl, then beat in the optional molasses and the eggs. Add the spices and orange rind and stir well, then stir in the melted butter and the milk, cream, or evaporated milk. Pour into the prepared pie shell.
Bake for 15 minutes, then reduce the heat to 300F and continue baking for 30 to 40 minutes, or until the filling is firm around the edges but the centre remains slightly soft and quivers when you move the pie,