1 (10 ounce) package sweet potatoes
1/2 cup butter
1 teaspoon vanilla extract
1 (8 ounce) can evaporated milk
1 (8 ounce) package cream cheese
1/2 cup chopped onion
1/2 cup melted butter
1 1/2 cups sour cream
1 (8 ounce) container frozen whipped topping, thawed
Preheat oven to 350 degrees F (175 degrees C). Grease and flour two 9 inch round baking pans.
Bring a large pot of water to a boil. Add sweet potatoes and cook for about 15 minutes, stirring occasionally. Drain and mash with a potato masher or spoon.
Melt butter in a medium saucepan over medium heat. Stir in vanilla, milk, cream cheese and onion. Bring mixture to a low boil.
Bring a large pot of water to a boil. Add sweet potatoes and cook for about 5 minutes, stirring occasionally. Drain and mash with potato masher or spoon.
Pour half of the mashed sweet potatoes into the prepared pan. Bake in the preheated oven for 25 minutes, until potatoes are tender.
In a medium bowl, beat cream cheese in a medium bowl until creamy. Mix in sour cream. Spread over sweet potato mixture. Return excess mixture to pan. Place another layer of sweet potatoes on top of the first one.
Bake for another 10 minutes, or until golden brown. Remove from oven and cool completely. Spread cream cheese mixture over sweet potato layer and refrigerate for several hours.