Heat a large skillet over medium-high heat. Add oil; swirl to coat. Add onion; sauté 5 minutes or until tender. Place onion in a large bowl.
Cook rice in a large pot of boiling water 5 minutes. Drain.
Stir rice and next 5 ingredients (through allspice) into onions. Spoon onion mixture into an 8-inch square glass or ceramic baking dish coated with cooking spray. Sprinkle evenly with Parmesan cheese. Cover and bake at 325° for 40 minutes. Uncover and bake an additional 5 minutes. Top with parsley, if desired.