For the filling, combine the mashed sweet potatoes, light brown sugar, butter, milk, eggs, vanilla extract and salt.
Add the flour about ¼ - ½ cup depending on the moisture content of the sweet potatoes.
Place filling in greased baking dish. Set aside.
Preheat oven to 375 degrees Fahrenheit.
For the crumble, combine with fork flour, dark brown sugar, spices and butter.
Mix until the mixture forms a crumble texture. Place crumble on top of the sweet potato filling.
Place into the oven middle rack and bake for 35-40 minutes or until golden brown.
Remove from oven and top with mini marshmallows. Place back into oven at 450 degrees Fahrenheit or broil to lightly brown the mini marshmallows.
Keep and eye on the mini marshmallow the can brown very quickly. Cool and Enjoy.