Add first 5 ingredients to food processor bowl; pulse 10 times. Set aside.
Roll out pizza dough; cut into 4 squares. Place on a baking sheet coated with cooking spray. Roll each square to 1/8-inch thickness. Spoon one-fourth of spinach mixture onto center of each square; top evenly with mushrooms and mozzarella cheese. Moisten edges of each square with water; bring corners to center, pressing edges to seal. Bake at 425° for 12 to 14 minutes or until golden. Serve with pasta sauce.