Move oven rack to lowest position. Heat oven to 450°F. Spray 12-inch pizza pan with cooking spray.
In medium bowl, stir baking mix and very hot water until soft dough forms; beat vigorously 20 strokes. Press dough in pizza pan, using fingers dipped in baking mix; pinch edge to form 1/2-inch rim. Spread pizza sauce over dough. Sprinkle with Italian seasoning and mozzarella cheese.
Bake 10 to 12 minutes or until crust is golden and cheese is bubbly.
Cut American cheese slices into desired shape with 2-inch cookie cutters. Arrange shapes on pizza. Let stand 1 to 2 minutes or until American cheese is melted.