Preheat grill to 375-400 degrees. Lay the sliced apples on a large sheet of foil, about 12 inches wide. Sprinkle apples with brown sugar and cinnamon, then add button top. Cover with another piece of foil and seal tightly. Place the foil packet on indirect heat on the grill, close the lid, and cook for about 20 minutes. Carefully remove the packet from the grill, pierce a hole on top to release steam, then open and serve.
You can optionally add a little caramel sauce, nuts, oats or granola, or honey. And of course, a dollop of vanilla ice cream!
Total time 25 minutes. Provides 2 servings.