1. Prepare the Sloppy Joe Filling

Start by heating a large skillet over medium heat. Add the ground beef and cook, breaking it up with a spatula, until browned and fully cooked through, about 6-8 minutes. Drain any excess fat from the beef.

Add the chopped onion and bell pepper (if using) to the skillet and cook for 3-4 minutes, or until the vegetables have softened and the onion becomes translucent. Add the minced garlic and cook for another 30 seconds, or until fragrant.

2. Make the Sauce

Once the beef and vegetables are cooked, stir in the ketchup, tomato paste, brown sugar, Dijon mustard, Worcestershire sauce, apple cider vinegar, smoked paprika, chili powder, salt, and pepper. Mix everything together until the beef is evenly coated with the sauce.

Bring the mixture to a simmer, stirring occasionally, and cook for an additional 5-7 minutes, allowing the sauce to thicken slightly and the flavors to meld together. Taste and adjust the seasoning with more salt, pepper, or additional vinegar if needed.

3. Assemble the Sliders

While the Sloppy Joe filling is simmering, preheat the oven to 350°F (175°C). Lightly grease a baking dish or line it with parchment paper. If you’re using slider buns that are connected in a sheet (like Hawaiian rolls), leave the buns intact for easier assembly.

Place the bottom halves of the slider buns in the prepared baking dish. Spoon a generous amount of the Sloppy Joe filling onto each bun, making sure to evenly distribute the mixture. Top each slider with a slice of cheese, allowing it to melt into the filling.

4. Top and Bake the Sliders

Place the top halves of the slider buns on top of the cheese, completing each sandwich. If desired, brush the tops of the buns with melted butter for extra flavor and a golden finish.

Cover the baking dish with aluminum foil and bake for 10-12 minutes, or until the sliders are heated through and the cheese has melted. For an extra crispy top, remove the foil for the last 2 minutes of baking.

5. Serve the Sliders

Once the sliders are done, remove them from the oven and let them cool slightly before serving. Use a sharp knife to cut between the buns, separating each slider. Serve hot, and enjoy the delicious Sloppy Joe Sliders with your favorite sides.