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.