In a large bowl, combine cream cheese, cheddar cheese, green onion, Worcestershire sauce, garlic powder, salt, and cayenne (if using). Mix until well blended.
Shape mixture into a ball. Wrap in plastic wrap and refrigerate for at least 1 hour (or up to 24 hours) to firm.
Place crushed Ritz crackers on a plate. Roll the chilled cheese ball in the crumbs, pressing gently to coat evenly.
Serve immediately or refrigerate until ready to serve. Serve with additional crackers, pretzels, or vegetable sticks.
Tips
For best flavor, let the cheese ball sit at room temperature for 15 minutes before serving.
To crush Ritz crackers, place them in a zip-top bag and crush with a rolling pin.
Can be made up to 2 days ahead; coat with crumbs just before serving.
Add 1/4 cup crumbled cooked bacon for extra flavor.