Heat gas or charcoal grill to medium. Spray the top side of each foil sheet with nonstick cooking spray.
Place one fourth of sweet potatoes and apples in center of each foil sheet. Sprinkle each with 1/2 teaspoon garlic, 1/2 teaspoon ginger and 1/4 teaspoon cinnamon. Top with 1/2 tablespoon butter, cut into small pieces.
Place two sausage pieces on top of sweet potatoes and apples. Bring up the sides of the foil. Double fold the top and ends to seal the packets, leaving room for heat circulation inside. Repeat to make 4 packets.
Place packets on grill and heat 20 to 25 minutes until sausage reaches 160°F.