Place the dried beans in a pot of water covered by a few inches of water and let soak overnight. Drain the beans, place them back in the pot with fresh water and bring to a boil. Simmer for one hour, then drain, reserving the liquid. See NOTE.
In a Dutch oven or other oven-proof pot fry the bacon until crispy then add the onions and cook until soft and translucent, 5-7 minutes. Add the garlic and cook for another minute.Stir in the tomato sauce, molasses, brown sugar, apple cider vinegar, mustard, Worcestershire sauce, smoked paprika, salt, pepper and bay leaf.Add 1 1/2 cups of the reserved bean water and the beans.Bring everything to a simmer for a minute or two to heat it up. In the meantime preheat the oven to 325 degrees F.
Transfer the Dutch oven with the lid on to the middle rack of the oven. Bake for 2 to 3 hours or until the beans are tender and the sauce has thickened, removing the lid during the last 20-30 minutes to help the sauce thicken. NOTE: If at any point during the cooking process too much liquid evaporates and the beans get dry, add a little more of the reserved bean water. The beans themselves can vary from batch to batch and you may end up either needing to add more liquid if the beans are too dry or you may need to bake the beans longer with the lid off if there is too much liquid. Adjust as needed.Add more salt the pepper to taste.Serve immediately or let cool completely and refrigerate until ready to serve. Can be reheated on the stovetop or in the microwave.
SLOW COOKER METHOD: Follow steps 1 and 2 and then pour everything into the slow cooker. Cook on LOW for 6-7 hours or on HIGH for 3-4 hours or until the beans are tender. Open the lid for the last 30 minutes or longer until the sauce has thickened. If the beans are too thick at any point and too much liquid has evaporated, stir in a little extra water.
Depending on the age and storage condition of the beans some can remain hard even after hours of cooking. A classic trick is to add 1/4 teaspoon of baking soda to the beans while you’re boiling them (1/4 teaspoon for every pound of beans). Be careful though: If too much is added or if it’s added to beans that aren’t too hard, you could end up with mushy beans.