For rib glaze: Mix the first 7 ingredients in a small bowl. Using a small sharp knife, loosen the membrane from the underside of each rib rack and pull off (or score membrane). Rub 1 tablespoon seasoning mix into each side of each rib rack. Place ribs in a large roasting pan. Cover and chill for at least 6 hours and up to 1 day.
For basting sauce: Whisk ingredients #9 through #14 together in a medium bowl to blend.
Preheat oven to 325°F. Lift ribs from pan. Scatter onion, cinnamon stick, and ginger in a pan. Pour in the remaining 1 1/4 Apple Cider Vinegar. Return ribs, meat side down, to pan; cover pan with foil. Roast ribs until the meat is tender and begins to pull away from bones, about 2 hours. Uncover; cool at least 30 minutes and up to 2 hours.
Prepare barbecue (medium-high heat). Grill ribs until heated through and slightly charred, about 5 minutes per side. Brush generously on all sides with basting sauce. Grill until sauce becomes a sticky glaze, about 3 minutes longer per side. Transfer rib racks to cutting board. Cut racks between bones into individual ribs. Arrange on a platter and serve, passing remaining sauce separately.