1Heat oven to 425°F. Spread cauliflower in single layer on nonstick cookie sheet; spray cauliflower with cooking spray. Sprinkle with salt and pepper; toss well. Roast 15 minutes. Stir; roast 5 to 10 minutes longer or until tender and golden brown.
2Meanwhile, in 10-inch skillet, cook bacon over medium heat until crisp. Remove with slotted spoon to paper towel-lined plate. Cook onion in bacon drippings, stirring occasionally, until golden. Remove with slotted spoon to plate with bacon.
3In large bowl, toss roasted cauliflower, bacon and onion. In small bowl, beat oil, vinegar, sugar, mustard and paprika with whisk until smooth. Pour dressing over cauliflower mixture; toss to coat. Season with salt and pepper to taste. Cover; refrigerate at least 1 hour until chilled or overnight.