1. Bring the apple cider to a boil in a small saucepan. Cook until cider is reduced to 1/4 cup (about 5 minutes). Remove from heat, and cool to room temperature.
2. Heat oil in a large Dutch oven over medium-high heat. Add onion to pan; sauté 3 minutes. Add curry powder and garlic to pan; sauté 1 minute, stirring constantly. Add cauliflower, broth, and apple; bring to a boil. Cover, reduce heat, and simmer 15 minutes or until cauliflower is very tender.
3. Remove pan from heat; cool 5 minutes. Place half of cauliflower mixture in a blender. Remove center piece of blender lid (to allow steam to escape); secure blender lid on blender. Place a clean towel over opening in blender lid (to avoid splatters). Blend until smooth. Pour into a large bowl. Repeat procedure with remaining cauliflower mixture. Return to pot. Stir in half-and-half; cook over medium heat 5 minutes or until thoroughly heated (do not boil). Remove from heat; stir in juice, salt, and 1/8 teaspoon pepper. Ladle about 1 cup soup into each of 8 bowls; drizzle each serving with 1 1/2 teaspoons cider reduction. Garnish with coarsely ground pepper, if desired.