Preheat your oven to 350°F. In a large, oven-safe Dutch oven or skillet, cook the chopped bacon over medium heat until it begins to crisp but isn't completely done, about 5-7 minutes.
Add the diced onion and bell pepper to the bacon and drippings. Cook until the vegetables soften and the onion becomes translucent, about 4-5 minutes. Add the minced garlic and cook for an additional 30 seconds until fragrant.
Add the drained and rinsed beans to the pot. In a separate bowl, whisk together ketchup, molasses, brown sugar, mustard, apple cider vinegar, Worcestershire sauce, smoked paprika, black pepper, and cayenne (if using). Pour this sauce over the bean mixture and stir gently to combine.
Cover the Dutch oven with a lid (or transfer the mixture to a baking dish and cover with foil) and bake in the preheated oven for 45 minutes. Remove the cover and bake for an additional 15-20 minutes until the top develops a slight caramelization and the sauce has thickened.
Allow the beans to rest for 10-15 minutes before serving. This resting period allows the flavors to settle and the sauce to achieve that perfect consistency.