Preheat the oven to 275°F
Remove the membrane from the back of the ribs
Pat the ribs dry
Season both sides with salt, pepper, and dry rub
Wrap the ribs tightly in foil
Place the wrapped ribs on a baking sheet
Bake for 2.5 to 3.5 hours for baby back ribs
Bake for 3.5 to 4.5 hours for spare ribs
Check for tenderness with a fork
Unwrap the ribs carefully
Brush with barbecue sauce if desired
Increase oven temperature to 400°F
Return the ribs to the oven uncovered for 10 to 15 minutes
Rest the ribs for 10 minutes before serving