Preheat the oven to 350°F (175°C).
In a large mixing bowl, combine the mashed sweet potatoes, sugar, salt, vanilla extract, eggs, milk, and ½ cup melted butter. Beat until smooth and well-mixed.
Pour the sweet potato mixture into a buttered baking dish, spreading it evenly.
In a separate bowl, mix the brown sugar, flour, ⅓ cup melted butter, and chopped pecans until well combined.
Sprinkle the pecan topping evenly over the sweet potato mixture.
Bake in the preheated oven for 30 minutes, or until the topping is golden brown and crisp.
Serve warm and enjoy!
