Pre-heat grill to 350°F, set up for indirect cooking.
Cook whole sweet potatoes on the grill for 30-45 minutes, turning halfway through.
Cool sweet potatoes and then peel them. (Peel removes very easily once cooled.)
Cut sweet potatoes into ¼” thick rounds.
Lay the sweet potatoes into a backing dish.
Sprinkle1 c. brown sugar evenly over the sweet potatoes.
Drizzle with orange juice and also 1 c. corn syrup.
Place cubes of butter on the sweet potatoes.
Place the orange slices on the sweet potatoes.
Drizzle the remaining 1 T. corn sugar and 1 T. brown sugar on the orange slices.
Place the baking dish, uncovered, on the grill, and bake for 30-45 minutes.