Preheat oven to 425°F.
Slice sweet potatoes into rounds, about 1/2 inch thick. Line on parchment lined baking sheet. Bake for 12-15 minutes, until softened, but just before they are soft enough to serve.
In a small bowl, combine maple, cranberries, pecans, and brown sugar if desired. (I made this once with and once without, liked both!)
When sweet potatoes are ready, remove from oven, and sprinkle with cinnamon and sea salt. On each sweet potato round, top with 2-3 marshmallows and a small spoon of cranberry pecan mix. This part can be tricky because the cranberries will want to roll away but just place them where it makes the most sense.
Set the oven to 350°.
Place the baking sheet back into the oven and bake another 6-8 minutes or until the marshmallows are cooked to your liking.
Remove from oven, allow to cool and serve!