Combine Cheeses: In a large bowl, mix shredded cheddar, Monterey Jack, and softened cream cheese.
Add Wet Ingredients: Stir in mayonnaise and diced pimentos until well blended.
Season: Add garlic powder, onion powder, smoked paprika, cayenne (if using), salt, and pepper. Adjust to taste.
Mix Thoroughly: Use a hand mixer or spatula to blend until creamy and smooth (about 2–3 minutes).
Chill: Cover and refrigerate for at least 1 hour before serving to let flavors meld.
Serve: Enjoy with crackers, celery sticks, or as a sandwich spread.