Preheat your oven to 350°F (175°C).
In a mixing bowl, combine the mashed sweet potatoes, brown sugar, melted butter, milk, vanilla extract, beaten eggs, and salt. Mix well.
Transfer the mixture to a baking dish.
In another bowl, mix together the brown sugar, gluten-free flour, melted butter, and chopped pecans for the topping.
Sprinkle the topping evenly over the sweet potato mixture.
Bake for 30 minutes, or until the topping is golden brown.
Let it cool slightly before serving. Enjoy!