Heat butter in a skillet; add onion and cook until onion is transparent.
Toss lightly with bread cubes, apple, sauerkraut, and caraway seed.
Sprinkle both sides of sparerib sections with salt and pepper; place one sparerib section on rack of a shallow roasting pan.
Spread stuffing over it; cover with second section.
Fasten the sections together with skewers.
Roast at 350Â°F for 1 1/2 hours, or until meat is tender when pierced with a fork.
Remove skewers; cut spareribs into serving-sized pieces and serve with the stuffing.