Spread potatoes onto bottom of 12-inch pizza pan sprayed with cooking spray; drizzle with butter.,Bake 30 min. or until lightly browned. After 25 min.| cook eggs in nonstick skillet on medium-low heat 3 to 5 min. or until set| stirring occasionally.,Spread eggs over potatoes; top with remaining ingredients. Bake 5 to 7 min. or until cheese is melted.