I browned ground beef and then poured in some ketchup, mustard, a little barbecue sauce, a bit of apple butter (or just use apple butter barbecue sauce), some vinegar, brown sugar, and some salsa (my preference for this is peach mango salsa). I just add this directly to the meat in the pan but I’m used to what the proper proportions are.
You can always mix the sauce ingredients in a bowl first and adjust to your taste. Other possible additions are Worcestershire sauce, onions, green peppers, celery, garlic, beer, and bourbon pepper. The fun part is then embellishing the tops of the buns to make into “goblin faces”. If your child is old enough, you can let them pick and choose from an assortment of foods you put out and they can create their own faces. I used celery leaves for hair, carrots for ears, red pepper for a mouth, a piece of pickle for a nose, and olives for eyes but there are many other possible options.