Preheat your grill or campfire to medium heat. If using a grill, lightly oil the grill grates with vegetable oil to prevent sticking.
In a mixing bowl, combine the mini marshmallows, chocolate chips, and peanut butter until well mixed.
Carefully fill each sugar cone with the marshmallow mixture, packing it in tightly.
If desired, sprinkle crushed graham crackers and chopped peanuts on top of the filling for added texture and flavor.
Wrap each filled cone in aluminum foil, making sure it is sealed tightly to prevent any filling from leaking out.
Place the wrapped cones on the grill or near the campfire for about 5-7 minutes, turning occasionally, until the chocolate is melted and the marshmallows are gooey.
Carefully unwrap the foil (it will be hot!) and enjoy your delicious campfire cones while they are warm.