01 - Preheat the oven to 425°F. Line a large baking sheet with parchment paper.
02 - Place cauliflower florets in a bowl, drizzle with olive oil, and season generously with salt and pepper. Toss until evenly coated.
03 - Spread cauliflower in a single layer on the prepared baking sheet. Roast for 25–30 minutes, flipping halfway through, until golden brown and tender with crispy edges.
04 - While cauliflower roasts, whisk together mayonnaise, sour cream, chili powder, smoked paprika, garlic powder, and lime juice in a large bowl until smooth and well combined.
05 - Transfer the hot roasted cauliflower directly into the bowl with the sauce. Toss gently but thoroughly to ensure every floret is evenly coated.
06 - Add half of the cotija cheese, half the cilantro, red onion, and jalapeño (if using). Toss again to distribute toppings evenly.
07 - Transfer to a serving platter. Sprinkle with remaining cotija cheese, extra chili powder to taste, and remaining cilantro. Serve immediately with lime wedges on the side.