Preheat oven to 375 degrees F. Spray a 9x13-inch baking dish with nonstick cooking spray; set aside.

In a small bowl, whisk together all sauce ingredients and set aside. Slice rolls horizontally (keeping them connected) and place the bottom halfinthepreparedpan. Spreadthesauceonthe inside of both halves of the rolls; set aside.

Add ground beef and onion to a large skillet over medium-high heat. Cook, breaking up the meat, until cooked through and onion is tender. Drain excess grease then season with salt and pepper.

Spread beef mixture over the bottom half of the rolls then top with cheese, pickle slices and the top half of rolls.

Brush melted butter over the top of the sliders, sprinkle sesame seeds on top and cover the pan with foil. Bake covered for 15 minutes then remove foil and cook an additional 5 minutes, or until cheese is melted.