1. Preheat oven to 375°.
2. Place cauliflower on a baking sheet coated with cooking spray. Lightly coat cauliflower with cooking spray. Bake at 375° for 30 minutes or until cauliflower begins to brown on the bottom. Turn cauliflower over; bake 5 minutes. Add almonds to pan; bake an additional 5 minutes or until almonds are browned.
3. Melt butter in a large saucepan over medium heat. Add onion and garlic; cook 4 minutes, stirring occasionally. Add apple; cook 3 minutes. Add curry powder; cook 2 minutes, stirring frequently. Stir in cauliflower, almonds, 4 cups water, salt, pepper, and bay leaf; bring to a simmer. Cover and cook 30 minutes or until cauliflower and apple are very tender. Discard bay leaf. Place half of soup 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 soup. Return soup to pan; stir in half-and-half. Top soup with yogurt and chives; sprinkle with cracked black pepper.