Preheat the oven to 350°F (175°C).
Place the creamy mashed sweet potatoes in a suitable baking dish.
In a medium mixing bowl, blend together melted butter, milk, brown sugar, vanilla extract and salt until incorporated.
Pour this mixture over the sweet potatoes in an even layer before stirring it all together.
In another separate bowl, whisk the eggs for a few seconds before pouring over the sweet potatoes.
Finally, in yet another bowl, combine all of the topping ingredients and mix until it forms a crumbly texture. Sprinkle this mixture evenly over the casserole.
Place in the preheated oven and bake for 45 minutes, or until the casserole is bubbling and the top is golden brown.
Allow it to cool before serving.