• Whisk together brown sugar, salt, and spices in a small bowl.
• Line a 17- by 12- by 1-inch heavy-duty baking pan with a double layer of foil, then oil foil.
• Pat ribs dry and arrange in baking pan. Rub ribs all over with spice mixture and marinate, meaty sides up, covered and chilled, 2 1/2 hours. *I usually omit this step, and pop 'em straight into the oven once rubbed down with spices.
• Bring ribs to room temperature, about 30 minutes.
• Put oven rack in middle position and preheat oven to 350°F.
• Cover pan tightly with foil; bake 1 1/4 hours. Remove foil.

Make sauce while ribs bake:

• Cook onion, garlic, and ginger in oil in a 2-quart heavy saucepan over moderate heat, stirring occasionally, until softened, about 6 minutes. Add remaining ingredients and simmer, uncovered, stirring occasionally, 15 minutes.
• Purée sauce in 2 or 3 batches in a blender until smooth (use caution when blending hot liquids). *I used a hand immersion blender - works beautifully for these kinds of jobs.
• Remove top sheet of foil and continue to bake ribs, uncovered, basting generously with sauce and pan juices every 10 minutes and turning ribs after 20 minutes, 40 minutes total. Then turn on broiler and broil ribs, meaty sides up, 4 to 6 inches from heat until browned, about 3 minutes.