Preheat the oven to 350°F (175°C).
In a large skillet, combine the minced onion and ground beef. Cook over medium heat until the beef is browned.
If needed, drain any excess grease from the skillet. Add water, brown sugar, apple cider vinegar, Worcestershire sauce, and beef bouillon cube. Bring the mixture to a boil, then reduce the heat and simmer until the liquid evaporates.
Arrange the bottom halves of the slider buns in a baking dish. Spread the beef mixture evenly over the buns. Top with dill pickle slices and American cheese. Place the remaining bun halves on top.
In a small bowl, whisk together the melted butter, brown sugar, Dijon mustard, and Worcestershire sauce to make the butter sauce. Brush the sauce over the tops of the buns.
Cover the baking dish with foil and bake for 25 minutes.
Remove the foil and continue baking for an additional 5 minutes, or until the buns are golden and the cheese is melted.
Serve these mouthwatering Maid-Rite Sliders warm and enjoy!