(You can prepare sweet potatoes ahead of time, even a day before.)
Wrap sweet potatoes in aluminum foil and bake them at 350℉ until completely cooked through. (Time will depend on the size of the sweet potatoes.)
Unwrap sweet potatoes once they are done and set aside to cool down.
Making The Pie:
In a large mixing bowl, beat butter and sugar together.
Beat in eggs, one at a time.
Beat in evaporated milk and molasses.
Mash (or puree) cooked sweet potatoes and beat it into the pie filling mixture.
Add vanilla, cinnamon, and nutmeg. Blend everything well.
Pour sweet potato pie filling into the pie shell.
Bake at 425℉ for 15 minutes.
Mix chopped pecans with maple syrup until all evenly coated and set aside.
Lower temperature to 350℉, spread the pecan topping over the top of the pie and continue baking for about 40 more minutes.
Take out and let it cool completely.
Notes
Storing: Store the leftover pie in the refrigerator, covered air-tight with plastic wrap. Properly stores, sweet potato pie will be good for 3 to 4 days.
Freezing: If you plan to freeze the pie after baking, make it in a pie aluminum baking pan. The bake time will be altered slightly (by just a few minutes less). Bake the pie and make sure to cool it completely. Wrap cooled pie airtight first in plastic wrap and then in aluminum foil. You can even place it into a large zip-top freezer bag for more protection. Label and freeze for up to 3 months.