In a large bowl, combine the ricotta cheese, egg, garlic powder, onion powder, Italian-style seasoning and half the mozzarella cheese and mix well. Place a spoonful of mixture onto a slice of roast beef and roll. Repeat with remaining beef.
Spread 1/2 cup of the spaghetti sauce on the bottom of a 9x13 inch casserole dish. Place the beef rolls in the baking dish seam side down. Pour the remaining sauce over the beef rolls.
Bake covered at 375 degrees F (190 degrees C) for 40 minutes, add the remaining mozzarella cheese over the top and bake for an additional 3 minutes, uncovered, until cheese is melted.
