Preparation:
* Preheat oven to 350 F. Put sweet potatoes in a medium saucepan with water to cover. Cook over medium high heat until potatoes are tender. Drain the water and mash the potatoes.
* In a large bowl, mix together the sweet potatoes, sugar, eggs, salt, butter, milk and vanilla. Mix until it is smooth. Transfer the contents into a baking dish.
* Mix the sugar and flour in a bowl. Cut in the butter until the mixture is coarse. Stir in the pecans. Sprinkle the mixture over the sweet potato mixture.
* Bake in the preheated oven at 350 F for 30 minutes