Begin by heating your oven to 400°F and lining a baking sheet with tinfoil. Next, brush the potatoes with oil, poke a few sets of holes in them using a fork, and put them on the baking sheet. Allow the potatoes to bake for an hour, or until they are tender. When the potatoes are done, allow them to cool for at least ten minutes before proceeding to the next step.
When the sweet potatoes are cooled, slice them lengthwise. Then carefully scrape out the inside, leaving ¼" of potato in the shell. Place the potato insides into a bowl and stir in the butter, syrup, and seasonings until they are well combined.
Next, divide the filling between the potatoes and fill them. Divide the mini-marshmallows evenly among the skins and place them on top. Give them a gently push to make sure they stay in place. Then place them back in the oven to bake for 15 minutes before broiling them for 1-2 minutes so that the marshmallows brown. Watch them CAREFULLY so that they don't start on fire and burn. Serve and enjoy!