Butter a 9x13 dish and set aside (adjust pan size if altering batch size).
Pour marshmallows onto one or two lightly greased baking sheets (use fewer or more if adjusting batch size), depending on their size, being careful not to lose any mallows if they're not rimmed. Place under broiler and watch closely as they'll toast up quickly. Remove when they're dark brown. Set aside.
Cut into about 15 squares (as original recipe is written) and serve immediately! Will keep covered for a few days.
*Nutrition information is a rough estimate.