Preheat oven to 400 degrees. Melt butter and pour into a cookie sheet and spread evenly across the bottom. Generously sprinkle coconut, pecans, and brown sugar all over the butter. Place sweet potato halves face down on the butter and toppings.
Place in preheated oven and bake for 35 to 40 minutes, the topping should look nice and toasted. Flip sweet potatoes over and generously spoon the topping on top of the sweet potatoes. Bake 15 to 20 more minutes, until sweet potatoes are nice and soft.
For the Cinnamon Marshmallow Cream Topping:
Blend all ingredients together well with a hand mixer. Refrigerate until serving. Spoon onto baked sweet potato halves just before eating.