Drain the can of pineapple rings and reserve the juice. In a bowl, whisk together pineapple juice, soy sauce, brown sugar, garlic powder, ground ginger, and black pepper until sugar dissolves.
Pat pork chops dry. Add to a zip-lock bag or shallow dish. Pour two-thirds of the marinade over the pork. Reserve the remaining one-third separately for basting. Marinate for at least 30 minutes, up to 4 hours, refrigerated.
Remove pork from fridge 20 minutes before cooking.
Oven method: Preheat oven to 400°F. Sear chops in an oven-safe skillet over medium-high heat for 2 minutes per side. Spoon reserved marinade over chops, top each with a pineapple ring, and bake 12 to 15 minutes until internal temp reaches 145°F.
Grill method: Preheat grill to medium-high (400°F). Grill chops 5 to 6 minutes per side, basting with reserved marinade. Grill pineapple rings alongside for 1 to 2 minutes per side until caramelized. Pull at 145°F internal temp.
Rest 5 minutes. Top each chop with a pineapple ring and spoon pan glaze over the top. Garnish with parsley or green onions. Serve over white rice.