For an extra touch of flavor, consider adding a layer of finely chopped nuts or a drizzle of caramel to each cone before wrapping in foil. Use heavy-duty aluminum foil to prevent tearing and ensure the cones are fully sealed during cooking. Keep a close eye on the cones while they are cooking to prevent burning. The cooking time may vary depending on the intensity of the embers. If you don't have a campfire, you can bake these in the oven at 350°F (175°C) for about 8-10 minutes, or until the marshmallows are melted and the chocolate is gooey.