Preheat the oven to 400°F and line a baking sheet with aluminum foil.

Scrub the sweet potatoes thoroughly and pierce them all over with a fork to allow steam to escape. Place the sweet potatoes on the prepared baking sheet.

Bake for about 45 minutes, or until the sweet potatoes are tender when pierced with a fork.

While the sweet potatoes are baking, mix together the softened butter, brown sugar, chopped pecans, and ground cinnamon in a bowl. Use a fork to combine the ingredients well.

Once the sweet potatoes are done, remove them from the oven and carefully cut each one down the middle. Use a fork to gently mash the inside of each potato.

Spoon the butter mixture evenly into the center of each sweet potato. Top with a generous ¼ cup of mini marshmallows per potato.

Place the sweet potatoes back in the oven on the broil setting for 15-20 seconds, just until the marshmallows are golden brown. Watch closely to prevent burning.

Serve immediately and enjoy!