Soften cream cheese to room temperature. Stir together cream cheese, 1/2 cup cheddar cheese, onion powder, garlic powder, two tablespoons Sriracha, and half the green onions until well combined.
Cover bowl of cream cheese mixture with plastic wrap, and place in refrigerator for at least an hour until firm. Transfer cream cheese to a large piece of plastic wrap. (I use the same piece I used to cover the bowl.) Use the plastic wrap to mold the cheese into a ball, and then unwrap it.
In a large, flat bowl, stir together remaining cheddar cheese, one tablespoon of Sriracha, and green onions. Roll cheese ball in the Sriracha cheddar mixture until evenly coated. Place cheese ball back in refrigerator covered loosely with plastic wrap until ready to serve with crackers.