Preheat oven to 425 degrees
Combine breadcrumbs with half the parmesan cheese in a small bowl - stir - set aside
In another small bowl, combine ricotta, spinach & remaining parmesan cheese - fold together with a fork until well combined.
Lay the chicken out on a greased baking sheet & spread approx 2 tbsp of the spinach mixture on top of each piece.
Roll up each piece- securing the end with a toothpick
Beat the egg in a shallow bowl
Dip each chicken roll in the egg & then in the breadcrumb mixture to coat
Place seam side down, back on the baking sheet & bake 25 minutes or until internal temp reaches 165 degrees
Remove from oven & spoon 1-2 tbsp of the tomato or marinara sauce over each chicken roll
Top with mozzarella cheese & return to oven for another 5-8 minutes to melt