Preheat oven: Preheat your oven to 350°F (175°C).
Cook bacon: In a large skillet over medium heat, cook the chopped bacon until crispy. Once the bacon is cooked, remove it from the skillet and place it on a paper towel to drain excess grease. Reserve the bacon drippings in the skillet.
Sauté onions: In the same skillet, add the diced onion to the reserved bacon drippings. Cook until the onions are soft and translucent, about 5-7 minutes.
Combine ingredients: In a large bowl, combine the cooked bacon, sautéed onions, baked beans, brown sugar, molasses, Dijon mustard, apple cider vinegar, smoked paprika (if using), salt, and pepper. Stir well to combine.
Bake: Transfer the mixture to a baking dish (9×9-inch or equivalent). Cover the dish with aluminum foil and bake for 30 minutes. Then, remove the foil and bake for an additional 15-20 minutes, or until the beans are bubbly and slightly caramelized on top.
