Prep the oven and pan. Heat your oven to 350°F (175°C).
Line a 9x13-inch baking dish with parchment or lightly grease it.
Cook the bacon. Pan-fry or bake until crisp. Drain on paper towels and chop into small pieces.
Mix the chicken filling. In a bowl, combine shredded chicken, BBQ sauce, ranch dressing, chopped bacon, and a pinch of salt and pepper. Add red onion and jalapeños if using.
Taste and adjust seasoning.
Slice the rolls. Without separating individual rolls, slice the entire sheet horizontally to make a top and bottom. Place the bottom half in the baking dish.
Add the cheese. Lay half the cheese slices on the bottom rolls. Spread the chicken mixture evenly over the cheese.
Top with the remaining cheese slices.
Cap the sliders. Place the top half of the rolls over the filling, pressing lightly to level.
Make the butter topping. Stir melted butter with garlic powder and onion powder. Brush generously over the tops. Sprinkle with sesame seeds or everything seasoning if you like.
Bake. Cover the pan loosely with foil and bake for 12–15 minutes.
Remove the foil and bake another 5–7 minutes until the cheese is melted and the tops are lightly golden.
Rest and slice. Let the sliders sit for 5 minutes to set. Use a serrated knife to cut along the roll lines. Serve warm.