In a large oven-safe skillet or Dutch oven, heat over medium-high heat and add the coarsely chopped thick-cut bacon. Cook until the bacon begins to crisp and renders its fat, about 5-7 minutes. Stir occasionally to ensure even cooking and avoid burning. Once done, use a slotted spoon to transfer the bacon onto a paper towel-lined plate, leaving the drippings in the pan.

In the same skillet with the bacon drippings, add the finely diced sweet onion. Cook on medium heat for about 5 minutes, stirring frequently, until the onions become translucent and slightly golden.

Lower the heat to medium-low and stir in the canned pork and beans, followed by the Red Gold ketchup, dark brown sugar, and drained pineapple tidbits. Add the yellow mustard, apple cider vinegar, salt, and black pepper. Stir until everything is well combined and heated through.

Preheat your oven to 350°F (175°C). Once fully combined, place the skillet (or Dutch oven) uncovered in the preheated oven. Bake for about 1 hour, or until the mixture is bubbling and the top begins to caramelize slightly.

After baking, carefully remove the pan from the oven and let it cool for a few minutes. Serve the savory beans warm as a delightful side to your favorite grilled meats.