Preheat Your Oven: Start by preheating your oven to 350°F (175°C).
Combine Ingredients: In a large mixing bowl, combine the baked beans, kidney beans, sliced hot dogs, and chopped onion.
Mix in the Goodness: Stir in the barbecue sauce, mustard, Worcestershire sauce, salt, and pepper until everything is well combined.
Bake Your Casserole: Pour the mixture into a greased baking dish and, if you'd like, sprinkle some shredded cheddar cheese on top for that extra touch of flavor.
Watch It Cook: Place the dish in the oven and bake for about 30-35 minutes until it's heated through and bubbly.
Serve and Enjoy: Take it out from the oven, let cool slightly, then dig in and enjoy this delightful meal!