Heat oven to 400°F. In large bowl, toss chicken and Buffalo wing sauce until well coated. Stir in cheeses and celery. Pour into ungreased 9-inch glass pie plate.
In medium bowl, mix Bisquick™ mix, cornmeal, milk and egg. Pour over chicken mixture; spread to cover.
Bake 25 to 30 minutes or until topping is golden brown. Cut into wedges; drizzle with blue cheese dressing.