Preheat oven to 325 degree.
In a medium bowl, combine sweet potatoes, sugar, eggs, butter, milk, salt and vanilla extract. Beat with electric mixer until smooth.
Transfer the mix into greased baking dish.
In another medium bowl, combine brown sugar, flour, butter and pecans.
Mix the ingredients with hands until the crumbles form.
Sprinkle the pecan crumble mix over the sweet potato mixture in the baking dish.
Bake in the oven for 35 - 40 minutes or until the topping is brown.