01 - Preheat oven to 425°F. Line a baking sheet with parchment paper.
02 - Spread cauliflower florets on the baking sheet, drizzle with olive oil, and season lightly with salt and black pepper. Roast for 20–25 minutes until golden and tender, stirring halfway through. Let cool.
03 - In a large bowl, whisk together mayonnaise, sour cream, lemon juice, Dijon mustard, garlic powder, smoked paprika, salt, and pepper until smooth.
04 - Add roasted cauliflower, cherry tomatoes, romaine lettuce, green onions, crumbled bacon, and cheddar cheese (if using) to the bowl. Gently toss to coat everything in the dressing.
05 - Taste and adjust seasoning. Serve immediately or chill for up to 2 hours for enhanced flavor.