Preheat your oven to 425°F (220°C). Line a baking sheet with parchment paper for easy cleanup.
Wash the cauliflower head and pat it dry. Slice it into bite-sized florets, ensuring they are uniform for even roasting.
In a large bowl, whisk together the olive oil, smoked paprika, sea salt, and black pepper. Toss the cauliflower florets in this mixture until they are well-coated.
Spread the cauliflower florets onto the prepared baking sheet in a single layer, ensuring they are not overcrowded.
Roast in the preheated oven for 25 minutes, or until the edges are golden brown and the florets are tender, stirring halfway through for even cooking.
While the cauliflower is roasting, prepare the caper dressing. In a small bowl, whisk together the olive oil, sherry vinegar, and Dijon mustard until emulsified.
Stir in the chopped capers, minced garlic, and parsley. Season with salt and pepper to taste. Set aside.
Once the cauliflower is done, transfer it to a serving dish. Drizzle the caper dressing over the warm cauliflower, tossing gently to coat.
Serve immediately, garnishing with additional parsley if desired.