Build a campfire and allow the fire to burn until it has accumulated a bed of coals. Rake the coals into a flat bed on one side of the fire.
Cut biscuits in quarters.
Combine sugar and cinnamon in a small bowl. Toss 8 biscuit pieces in the cinnamon-sugar mixture until lightly coated.
Spray a sheet of foil with cooking spray, then arrange the 8 coated biscuit pieces in a single layer on top. Securely close to form a foil packet. Repeat process with remaining dough to make 4 more packets.
Place foil packets over the fire and cook until biscuits are cooked and lightly browned, 8 to 10 minutes, flipping halfway through.
Remove from the fire. To serve, open each packet and drizzle monkey bread with melted butter and syrup.