Preheat the oven to 350°F
Line a 9x13-inch baking dish with parchment paper, you can also use a baking sheet if you like
Heat a medium skillet over medium-high heat
Add the ground beef and cook until browned, breaking it into crumbles as it cooks
Drain any excess grease and return the pan to the heat
Stir the Worcestershire sauce, garlic powder, and black pepper into the beef until evenly combined
Remove from the heat and set aside
In a medium bowl, beat the softened cream cheese until smooth with a hand mixer
Fold in the shredded cheddar cheese and about 2/3 of the ranch seasoning until well combined
Slice the slider buns in half, keeping the rolls connected in one sheet if possible
Place the bottom half in the prepared pan
Evenly spread the seasoned ground beef over the buns. Sprinkle with the diced jalapeños, crumbled bacon, and sliced red onion
Spread the cream cheese mixture evenly over the top buns and place the sheet of slider tops over the beef mixture
In a small pan over low heat, melt the butter
Add the remaining ranch seasoning and chopped parsley, then whisk together.
Brush generously over the tops of the buns
Cover loosely with aluminum foil and bake for 10 minutes. Remove the foil and bake for an additional 5-8 minutes, or until the tops are golden brown and the filling is hot and melty
Let the sliders cool for 2-3 minutes before slicing and serving