In a medium-sized bowl, add the smoked paprika, chipotle, roasted garlic powder, salt, cayenne (to taste), white pepper, thyme and onion powder; mix together. Add the shelled prawns and toss to coat evenly. Place into the refrigerator for at least 1 – 4 hours to infuse the flavors of the Creole blend fully into the shellfish and also lightly cure the prawns.