Preheat your oven to 350 degrees F. Grease a 1 ½ quart baking dish or spray with cooking spray.
In a large bowl, mix together sweet potatoes, sugar, salt and nutmeg with a large spoon. Add eggs and stir well to combine. Add melted butter (2 tablespoons), milk and vanilla, stirring well to combine. Pour into prepared baking dish, spread evenly and bake for 35 minutes.
Prepare the topping while the soufflé is baking. Stir together light brown sugar, flour, pecans and coconut in a large bowl. Drizzle with melted butter and stir well to combine.
Remove soufflé from oven after 35 minutes and top evenly with topping. Return to oven and bake for an additional 20 minutes.
Let stand 10 minutes before serving.