Stir together the mayonnaise, pimientos, Worcestershire, garlic powder, and cayenne in a large bowl; add the cheeses, stirring until blended. Store in the refrigerator up to 1 week.
Cook’s Note
Don't skip the step of rinsing your diced pimiento. Otherwise it will be too salty. For the creamiest pimiento cheese, buy the cheese in blocks and shred by hand.