Soak the beans overnight or for at least 2 hours in hot water. Drain and cook the beans with the packet of Cajun seasoning and the diced onions for 30-40 minutes, or until all the beans are soft.
Meanwhile, cook the bacon strips and then crumble them.
Drain the cooking liquid and return to the pot. Stir in the tomato sauce, brown sugar, cider vinegar, spicy mustard, garlic powder and crumbled bacon. Let simmer for about 10 minutes before serving. Season with salt and pepper.
(If you wish to keep them warm longer than 10 minutes, cover them so they don't dry out.
Serve as side dish, potluck dish or at your next football game party.