01 - If using dried beans, soak them overnight in plenty of water. Drain and simmer in fresh water for 45 to 60 minutes until tender but not mushy. Drain and set aside.
02 - Preheat the oven to 340°F (170°C).
03 - In a large ovenproof pot or Dutch oven, heat vegetable oil over medium heat. Add the chopped onion and bacon if using, sauté for 5 to 7 minutes until golden. Add garlic and cook for an additional minute.
04 - Stir in tomato paste, smoked paprika, and Dijon mustard. Cook for 1 minute until fragrant.
05 - Add brown sugar, molasses, apple cider vinegar, crushed tomatoes, salt, black pepper, and 1 cup of water. Stir thoroughly to combine.
06 - Fold the cooked or canned beans into the sauce. Bring to a simmer, then cover with a lid or foil.
07 - Transfer the pot to the oven and bake for 1 hour, stirring once halfway through. Add additional water if the mixture thickens too much.
08 - Remove the lid and bake for an additional 15 to 20 minutes to achieve a thick, caramelized sauce.
09 - Taste and adjust seasoning as needed. Serve warm.