Preheat oven to 350 degrees.
Spray a 11×7, 8x8 or 9×9 baking dish with non-stick spray.
For topping: Combine brown sugar, flour, nuts and butter in small mixing bowl and set aside.
To make the sweet potato filling: To the mashed sweet potato’s, add the melted butter, sugar, salt, and vanilla and stir well.
Mix in the beaten eggs thoroughly and pour the potato mixture in to your prepared baking dish.
“Sprinkle” the surface of the sweet potato mixture evenly with the topping mixture. (It’s wet, but use your fingers and sprinkle it over to get it as even as you can.)
Bake for 30 minutes uncovered and then allow to set at least 20 minutes before serving.