Heat oven to 425°F. Spray large cookie sheet with cooking spray. Unroll pizza dough on cookie sheet; press into 15x12-inch rectangle. Bake 6 to 8 minutes or until light golden brown.
In small bowl, stir together 1/2 cup plus 2 tablespoons of the cooking sauce (more sauce will make crust soggy) and the garlic. Spread sauce mixture evenly over partially baked crust. Sprinkle with chicken and cheese. Bake 8 to 10 minutes or until crust is golden brown. Sprinkle with tomatoes, green onions and Italian seasoning.
Meanwhile, heat remaining sauce in 1-quart saucepan until hot; serve with pizza as dipping sauce.