Preheat oven to 350°F/177°C. Grease and line a 9x5-inch rectangular pan. Set aside.

Mix together cake mix, egg and butter until well combined.

Pour in batter into prepared pan. Bake for 20-25 minutes until, center will still be soft. Let it cool to set. Cut into small cubes.

Place desired toppings inside a waffle cone. Place in the broiler to toast marshmallows or use a kitchen torch to toast them.