Preheat oven 400 degrees F.
Parbake pie shell for 10 to 12 minutes until lightly browned. Remove from oven.
In a stand mixer fitted with a paddle attachment mix together yams, eggs, vanilla, cinnamon, allspice and brown sugar until smooth.
Pour mixture into parbaked pie shell. Wrap the rim of the crust with foil. Place into oven at 325 degrees F and bake for 1 hour.
Remove from oven and allow to cool completely on a rack before cutting and serving.