In a large mixing bowl, combine the softened cream cheese and the shredded sharp cheddar. Use a hand mixer or a sturdy spatula to blend them together until the mixture is uniform and smooth. Using freshly shredded cheddar rather than pre-bagged cheese will result in a better texture.
Add the Worcestershire sauce, liquid smoke, garlic powder, and onion powder to the cheese mixture. Fold in the chopped green onions. Mix thoroughly to ensure the smoky flavor and spices are evenly distributed throughout the cheese.
Scrape the mixture onto a large piece of plastic wrap. Use your hands (outside the plastic) to form the cheese into a ball shape. Wrap it tightly and place it in the refrigerator for at least two hours. Chilling is essential as it allows the flavors to meld and the ball to firm up so it holds its shape.
In a small shallow bowl or on a plate, mix the chopped nuts with the smoked paprika and optional parsley. This mixture will provide a beautiful color and a satisfying crunch to the exterior of your cheese ball.
Once the cheese ball is firm, remove it from the plastic wrap. Roll the ball in the nut mixture, pressing gently so the coating adheres to the surface. Ensure the entire ball is evenly covered. Transfer to a serving platter and serve immediately or keep refrigerated until ready.