Place potatoes in a large pot filled with water. Boil potatoes until they can be easily pierced with a fork – approximately 45-60 minutes. While potatoes are still warm, gently peel off outer layer of skin and reserve.
Preheat oven to 350°F. In a large bowl using an electric mixer, blend sweet potato pulp, butter, eggs, evaporated milk, whole milk, sugar, nutmeg, cinnamon, lemon extract, and vanilla extract on medium speed until filling is smooth and creamy – approximately 7 minutes.
Gently spoon mixture into the pie crust. Place pie in oven on middle rack. Bake until golden brown – approximately 35-45 minutes. Let rest on rack 15 minutes and serve.