Sweet Potato Casserole

I soured the web for a recipe to replicate the Boston Market's sweet potato casserole. And I found one - the secret in addition to the crumb oat topping - is a secret, haha. It turned out really, really good.
Sweet potatoes scrubbed and washed:

Bake in oven for 60 minutes until tender:

Prepare the oat crumb topping:

Add ingredients to sweet potatoes:

Ready for the pan:

Place in dish and ready to bake (a layer of a little something special added between the sweet potatoes and crumb topping).

Bake for about 65 minutes. Remove from oven. Add mini marshmallows and let melt.