Step 1

Spray 5-quart slow cooker with cooking spray. Sprinkle chicken with celery salt, salt and pepper; arrange in slow cooker. Pour Buffalo sauce over chicken; stir in garlic. Cover; cook on High heat setting about 2 hours or until juice of chicken is clear when thickest part is cut (at least 165°F). Remove chicken and, using two forks, shred into bite-size pieces.

Step 2

Add cream cheese and Cheddar cheese to slow cooker; stir to combine. Cover; cook 15 minutes. Beat with whisk until cheeses have melted into sauce. Add rigatoni and shredded chicken; stir to combine. Cover; cook about 5 minutes or until hot. Garnish with blue cheese and green onions.