Place the boiled sweet potatoes or canned yams into a large mixing bowl.
Use a hand mixer to beat in the sugar, butter, eggs, vanilla, and milk until smooth and creamy.
Put the mixture in a greased 9x13 pan.
Topping: Combine the brown sugar, cubed butter, and flour in a small bowl. (I used a small food processor.)
Sprinkle the topping over the yams/sweet potatoes followed by the pecans.
Bake at 350 degrees for 40-45 minutes.