Break graham wafers into small bite-sized pieces. Mix in marshmallows and chocolate chips.
Stuff each sugar cone to the rim with marshmallow mixture. Wrap with double layer of foil to seal cone and filling completely.
Set on BBQ grill preheated to medium. Close lid and roast, turning occasionally, 5 to 8 min. Remove from grill. When cones are cool enough to handle, hold upright to unwrap. Serve warm.
Try add-ins such as white chocolate chips, banana slices, berries, toffee bits, nuts, dried fruit or toasted coconut, chocolate-coated candies.
To make in oven, place wrapped cones on baking sheet tray and bake at 350˚F (180˚C) 5 to 8 min.