Preheat oven to 425°.Heat a small skillet over medium heat. Add â…“ cup breadcrumbs to pan, and cook for 2 minutes or until toasted, stirring frequently. Remove from heat, and place in a shallow dish.Working with one piece at a time, dip frozen cheese cubes in egg, then dredge in breadcrumbs. Place cheese on a baking sheet coated with cooking spray. Bake at 425° for 5 minutes or until the cheese is softened and thoroughly heated.Pour the marinara sauce into a microwave-safe bowl. Microwave at HIGH 1 minute or until thoroughly heated, stirring after 30 seconds. Serve with mozzarella pieces.