Preheat oven to 375°F. Line a sheet pan with parchment paper.
Butterfly the pork loin: slice horizontally through the center without cutting all the way through. Open it like a book.
Cover with plastic wrap and pound to an even thickness (½–¾ inch).
In a bowl, mix cream cheese, bacon, spinach, cheddar, and green onions.
Spread filling evenly over the pork, leaving a 1-inch border.
Roll tightly, seam-side down. Tie with butcher’s twine if needed.
Season outside with garlic powder, onion powder, paprika, salt, and pepper.
Bake 50–60 minutes, or until a meat thermometer reads 145°F.
Rest 10 minutes before slicing for juicy, tender results.