I made this for our Thanksgiving Day feast, my first time ever making sweet potato casserole, and it was a big hit. My English sister-in-law had never heard of it and was quite curious. She gave it two thumbs up but wondered why it wasn't a dessert.
The original doesn't have marshmallows, but I added them after consulting with the family. They all agreed it needed the sweet, fluffy treats.
For the topping:*