Pre-heat oven to 250f
Soak beans in a plastic container overnight in just enough cold water to submerge them completely.
Place a Dutch oven over medium heat and stir in the bacon and onions until enough fat has rendered from the bacon to soften the onions, about 5 minutes. Stir in the tomato paste, dark brown sugar, and molasses.
Drain the beans. Add the drained beans to the Dutch oven. Add the vegetable broth to the Dutch oven and bring to a boil over high heat. Give them a stir and cover with the lid. Place the Dutch oven in the oven for 6 to 8 hours, or until the beans are tender.
When beans are tender, add in cayenne, black pepper and salt and allow to marry into mix for an hour on low heat.