In a large bowl, stir together the cream cheese, sour cream, Sharp Cheddar cheese, pimiento peppers, Worcestershire, garlic powder and sliced scallions until combined.
Arrange a piece of plastic wrap on your work surface then transfer the cheese mixture into the center. Gather up the sides of the plastic wrap and shape the cheese into a ball. Refrigerate it for 20 minutes.
Add the crushed pecans to a shallow bowl.
Remove the cheese ball from the fridge and discard the plastic wrap. Coat the cheese ball in the pecans, pressing them to adhere to the entire exterior of the cheese ball.
Serve the cheese ball immediately or re-cover it with plastic wrap and refrigerate it until ready to serve with crackers, pretzels or crudité.