Preheat oven to 400 degrees F.

 

Cream butter and sugar together. Add eggs and stir. Add yams and mix well. Add cinnamon and cornstarch. Stir in milk, vanilla and salt, making sure all ingredients are thoroughly mixed.

 

Pour into pie shell and bake 15 minutes. Lower heat to 350 degrees. Cook until knife comes out clean (20-30 minutes).