Carefully cut the two sweet potatoes into wedges no more than ½ inch think at any point. It is more important to have the wedges be of similar size.
Prepare the Mix
Add butter, brown sugar and cumin to a ziplock bag and mix
Add in the potato wedges and work the mixture to coat the potatoes
Grill the Sweet Potatoes
Bring the grill temperature to 350 degrees on direct heat
Carefully arrange the sweet potatoes on the grill
Grill each side for about 5 minutes
Notes
You can use a grilling vegetable basket, but it really isn't necessary. The wedges were large enough to pick up with tongs and lift up with the spatula.