Heat oven to 375°F. Lightly grease large cookie sheet with shortening or cooking spray. In medium bowl, mix 1/2 cup dressing and the garlic powder; stir in chicken.
Separate dough into 8 rolls. Press or roll each to form 4 1/2-inch round; place on cookie sheet. Divide chicken mixture evenly among rounds; top with bell pepper, tomato and Parmesan cheese.
Bake 15 to 18 minutes or until cheese is melted and edges are lightly browned. Drizzle with additional dressing.