. Mix the Marinade
In a medium bowl, combine the soy sauce, oil, apple cider vinegar, minced garlic, ketchup, garlic powder, onion powder, lemon zest, salt, and pepper. Whisk until blended.
Prepare the Ribs
Pat the baby back ribs dry with paper towels. Lay them meat-side down on a baking sheet. Use a small knife to loosen one corner of the membrane on the back, then pull it away and discard it.
Marinate
Transfer the ribs to a 9x13-inch dish. Pour the marinade over them and rub it over every surface. Cover and let the ribs sit for 30 to 60 minutes.
Get the Grill Ready
Clean and oil the grill grates well. Heat the grill to 500°F.
Make the Dry Seasoning
In a small bowl, stir together the smoked paprika, lemon pepper, kosher salt, smoked garlic powder, onion powder, black pepper, and cayenne if using.
Season the Ribs
Take the ribs out of the marinade and let the extra liquid drip off. Place them on a baking sheet and coat all sides with the spice mixture.
Cook the Ribs
Place the racks meat-side down over the center burner. Reduce the grill temperature to 300°F. A good setup is to switch off the middle burner and leave the outer burners on low. Cook for 30 minutes, then turn the ribs over. Keep grilling until the internal temperature reaches 190°F to 203°F. For firmer ribs, aim closer to 190°F. For more tender, fall-apart ribs, let them reach about 203°F.
Add the Sauce
When the ribs are about 5 degrees away from finished, brush the tops generously with barbecue sauce. Close the lid and continue grilling until fully cooked.
Let Them Rest
Take the ribs off the grill and place them on a baking sheet. Cover loosely with foil and let them rest for 30 to 60 minutes.
Serve
Remove the foil, slice the ribs, and serve warm.